This post may contain affiliate links. Please read my disclosure for more info.

Convert color codes (RGB, HSL, Hex, Long, CMYK)

Convert Color Codes with VBA

I often find myself converting between different formats of color codes; especially from hex to RGB and back again.  Rather than firing up Google and searching for color conversion tools online, I decided to write my own User Defined Functions in Excel, now I can calculate the result within a worksheet instead.

The functions in this post include the conversions for RGB, hex, HSL, CMYK and long formats.

Using these color conversion functions, I created an add-in which makes the conversion even easier.  Keep reading to find out how you can download the add-in for free.

Download the example file

I recommend you download the files which support this post, as you’ll be able to work along with examples.  This is the best way to learn.  You’ll be able to see the solutions in action, plus the file will be useful for future reference.  The support files are available for FREE to newsletter subscribers.

Click below to subscribe and gain access to the subscriber area.  You will also receive:

  • My favorite tips and tricks direct to your inbox
  • Exclusive content (which is only available to subscribers)
  • FREE tools and downloads

Download Icon

If you’re already a subscriber, click here to log-in to the subscriber downloads area.

The filename for this post is 0006 Convert color codes.zip.

Excel’s different color code formats

Even in Excel, there are four different methods of defining color; RGB, hex, HSL and long.

RGB

The RGB (Red, Green and Blue) color code is used within the standard color dialog box.

RGB color codes in the standard color picker

The individual colors Red, Green and Blue each have 256 different shades, which when mixed can create 16,777,216 different color combinations.

HSL

Within the standard color dialog box there is another code format; using the color model drop-down we can change to HSL.  HSL uses Hue, Saturation and Luminance to create the color.

HSL Color mode in color dialog box

HSL tries to define colors closer to the way humans think about colors.

  • Hue – is the degree on the color wheel from 0 to 360.  0 is red, 120 is green, 240 is blue.
  • Saturation – is a percentage of the amount of color included.  100% is full color, 0% is no color (i.e. all grey)
  • Luminance (or lightness) – is a percentage of grey.  0% is black, 100% is white.

Frustratingly, Excel does not handle HSL in the standard way.  Instead, Excel measures all the numbers where 0 is the lowest and 255 is the biggest.  But, it’s a quirk we can handle.

Long

The long color code is used by VBA when displaying the color property of an item.  The following macro displays the long code for the fill of the active cell.

Sub ActiveCellColor()

MsgBox "Long color code: " & ActiveCell.Interior.Color

End Sub

Select a cell and run the macro.

Long color code displayed in msgBox

The long code is a number from 0 to 16,777,215, where each separate number represents a color.  The relationship between RGB and long is based on a simple calculation:

Long = Red x 256 x 256 + Blue x 256 + Green

As an example:

  • Where Red: 33, Green: 115 and Blue: 70
  • The result calculates as 33 x 256 x 256 + 115 x 256 + 33    =    4,616,993

Long and RGB are related; they are just different ways of calculating the same number.

Hex

Hex color codes are similar to RGB as they also use 256 shades for each individual color.  The critical difference is that the hex system represents the numbers from 0 to 255 using just two characters.  This is possible because hex uses Base-16.

We generally use Base-10 in everyday life, which means that we have 10 digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) available.  As an example, the number 14 is created by using the formula (1 x base) + 4.  The base is 10, so the result is calculated as  (1 x 10) + 4, which equals 14.

For Base-16, there are 16 digits; however, as we don’t have enough number characters we use A, B, C, D, E and F to represent the numbers from 10 through 15.

As an example, the hex number AB equals 171.

  • A = 10
  • B = 11.
  • The calculation is (A x base) + B   =     (10 x 16) + 11   =    171

In hex, the lowest value is zero and the highest value is F (which is equal to  15).  Therefore, there are 16 possible individual digits.  This means that from two digits we can create 256 shades (16 x 16 = 256), which is the same as RGB.  Therefore, hex also has the same 16,777,216 combinations as RGB and long.

Hex codes are presented in reverse order to RGB, so if the hex color code is #467321 the last two characters represent red, the middle two characters represent green and the first two are blue.

Using the #467321 hex code as an example, the conversion to RGB would be:

  • Red: Hex value of 21 calculates as (2 * 16) + 1 = 33
  • Green: Hex value of 73 calculates as (7 * 16) + 3 = 115
  • Blue: Hex  value of 46 calculates as (4 * 16) + 6 = 70

The hex codes are used within the VBA properties to define color.

Hex code used within VBA

The color code in the screenshot above is: &H00467321&

  • & = Start character
  • H = Hex code
  • 00 = Tells VBA to use a custom color
  • 467321 = the Hex color code
  • & = End character

CMYK

Another common color code system is CMYK.  It is used primarily for printing, as it determines the amount of Cyan, Magenta, Yellow and blacK ink used in overlapping printed dots.

While Excel does not use CMYK, it is a common method, so I have included it within the scope of this post.

Become a VLOOKUP master with the Advanced VLOOKUP Cheat Sheet

  • Faster Calculation
  • VLOOKUP to the left
  • Automatically change the column number
  • Lookup with multiple criteria
  • Lookup with rows and columns
  • Wildcards

Download the VLOOKUP Cheat Sheet today!

Click the button below to subscribe, you’ll gain access to the subscriber area in which you can download the cheat sheet.

Download Icon (on mid-green background)

Advanced VLOOKUP Cheat Sheet Image

User Defined Functions for color conversion

In the section above, I’ve tried to explain how each method defines colors, but converting between them is a different matter entirely, and is much harder.  Thankfully, we can let Excel do the work for us.  Below are the UDF’s to convert between the various methods.

Remember! – To use VBA functions, the code must be included in a standard VBA code module.

RGB, hex and long are all based on whole numbers, so they should perfectly convert between each other.  CMYK and HSL involve decimal places and percentages and therefore could create small differences in their conversions.

Convert from RGB to hex

The following UDF calculates the hex value based on the RGB color codes.

Function GetHexFromRGB(Red As Integer, Green As Integer, Blue As Integer) As String

GetHexFromRGB = "#" & VBA.Right$("00" & VBA.Hex(Blue), 2) & _
    VBA.Right$("00" & VBA.Hex(Green), 2) & VBA.Right$("00" & VBA.Hex(Red), 2)

End Function

How to use the function:

The function contains 3 arguments, values between 0 and 255 for each individual Red, Green, or Blue value.

Hex from RGB

Convert from hex to RGB

The UDF below provides the Red, Green, or Blue value based on the hex color.

Function GetRGBFromHex(hexColor As String, RGB As String) As String

hexColor = VBA.Replace(hexColor, "#", "")
hexColor = VBA.Right$("000000" & hexColor, 6)

Select Case RGB

    Case "R"
        GetRGBFromHex = VBA.Val("&H" & VBA.Mid(hexColor, 5, 2))

    Case "G"
        GetRGBFromHex = VBA.Val("&H" & VBA.Mid(hexColor, 3, 2))

    Case "B"
        GetRGBFromHex = VBA.Val("&H" & VBA.Mid(hexColor, 1, 2))

End Select

End Function

How to use the function:

The function contains 2 arguments;

  1. the hex code
  2. the letter R, G or B, to represent the color to be returned

RGB from Hex

Convert from RGB to long

This UDF provides the long value based on the RGB color codes.

Function GetLongFromRGB(Red As Integer, Green As Integer, Blue As Integer) As Long

GetLongFromRGB = RGB(Red, Green, Blue)

End Function

How to use the function:

The function contains 3 arguments, values between 0 and 255 for each individual Red, Green, or Blue value.

RGB from Long

Convert from long to RGB

To convert from RGB to the long color code, use the following UDF.

Function GetRGBFromLong(longColor As Long, RGB As String) As Integer

Select Case RGB

    Case "R"
        GetRGBFromLong = (longColor Mod 256)

    Case "G"
        GetRGBFromLong = (longColor \ 256) Mod 256

    Case "B"
        GetRGBFromLong = (longColor \ 65536) Mod 256

End Select

End Function

How to use the function:

The function contains 2 arguments;

  1. the long code
  2. the letter R, G, or B, depending on which color we want to return.

Long from RGB

Convert from long to hex

The following UDF provides the hex code based on the long color code.

Function GetHexFromLong(longCode As Long) As String

GetHexFromLong = "#" & Application.WorksheetFunction.Dec2Hex(longCode)

End Function

How to use the function:

The function has only one argument, which is the long color code.

Hex from Long

Convert from hex to long

The UDF below converts the hex code into the long color code.

Function GetLongFromHex(hexColor As String) As Long

hexColor = VBA.Replace(hexColor, "#", "")
hexColor = VBA.Right$("000000" & hexColor, 6)

GetLongFromHex = Application.WorksheetFunction.Hex2Dec(hexColor)

End Function

How to use the function:

The function has only one argument, which is the hex code.

Long from Hex

Convert from RGB to HSL

The UDF below will return the degree of Hue, % of Saturation, or % of Luminance based on the RGB color codes.

Function GetHSLFromRGB(Red As Integer, Green As Integer, Blue As Integer, _
    HSL As String)

Dim RedPct As Double
Dim GreenPct As Double
Dim BluePct As Double
Dim MinRGB As Double
Dim MaxRGB As Double
Dim H As Double
Dim S As Double
Dim L As Double

RedPct = Red / 255
GreenPct = Green / 255
BluePct = Blue / 255

MinRGB = Application.WorksheetFunction.Min(RedPct, GreenPct, BluePct)
MaxRGB = Application.WorksheetFunction.Max(RedPct, GreenPct, BluePct)

L = (MinRGB + MaxRGB) / 2

If MinRGB = MaxRGB Then
    S = 0
ElseIf L < 0.5 Then
    S = (MaxRGB - MinRGB) / (MaxRGB + MinRGB)
Else
    S = (MaxRGB - MinRGB) / (2 - MaxRGB - MinRGB)
End If


If S = 0 Then
    H = 0
ElseIf RedPct > Application.WorksheetFunction.Max(GreenPct, BluePct) Then
    H = (GreenPct - BluePct) / (MaxRGB - MinRGB)
ElseIf GreenPct > Application.WorksheetFunction.Max(RedPct, BluePct) Then
    H = 2 + (BluePct - RedPct) / (MaxRGB - MinRGB)
Else
    H = 4 + (RedPct - GreenPct) / (MaxRGB - MinRGB)
End If

H = H * 60

If H < 0 Then H = H + 360

Select Case HSL

    Case "H"
        GetHSLFromRGB = H

    Case "S"
        GetHSLFromRGB = S

    Case "L"
        GetHSLFromRGB = L

End Select

End Function

How to use the function:

The function contains 4 arguments.  The R, G and B values, then the letter H, S, or L, depending on the value to be returned by the function.

HSL from RGB

The calculation for converting to HSL is based on the calculation from here: http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/

Convert from HSL to RGB

The following UDF calculates the RGB values based on the degree of Hue, a% of Saturation % of Luminance

Function GetRGBFromHSL(Hue As Double, Saturation As Double, Luminance As Double, _
    RGB As String)

Dim R As Double
Dim G As Double
Dim B As Double
Dim temp1 As Double
Dim temp2 As Double
Dim tempR As Double
Dim tempG As Double
Dim tempB As Double

If Saturation = 0 Then

    R = Luminance * 255
    G = Luminance * 255
    B = Luminance * 255

GoTo ReturnValue

End If

If Luminance < 0.5 Then
    temp1 = Luminance * (1 + Saturation)
Else
    temp1 = Luminance + Saturation - Luminance * Saturation
End If

temp2 = 2 * Luminance - temp1

Hue = Hue / 360

tempR = Hue + 0.333
tempG = Hue
tempB = Hue - 0.333

If tempR < 0 Then tempR = tempR + 1
If tempR > 1 Then tempR = tempR - 1
If tempG < 0 Then tempG = tempG + 1
If tempG > 1 Then tempG = tempG - 1
If tempB < 0 Then tempB = tempB + 1
If tempB > 1 Then tempB = tempB - 1

If 6 * tempR < 1 Then
    R = temp2 + (temp1 - temp2) * 6 * tempR
Else
    If 2 * tempR < 1 Then
        R = temp1
    Else
        If 3 * tempR < 2 Then
            R = temp2 + (temp1 - temp2) * (0.666 - tempR) * 6
        Else
            R = temp2
        End If
    End If
End If

If 6 * tempG < 1 Then
    G = temp2 + (temp1 - temp2) * 6 * tempG
Else
    If 2 * tempG < 1 Then
        G = temp1
    Else
        If 3 * tempG < 2 Then
            G = temp2 + (temp1 - temp2) * (0.666 - tempG) * 6
        Else
            G = temp2
        End If
    End If
End If


If 6 * tempB < 1 Then
    B = temp2 + (temp1 - temp2) * 6 * tempB
Else
    If 2 * tempB < 1 Then
        B = temp1
    Else
        If 3 * tempB < 2 Then
            B = temp2 + (temp1 - temp2) * (0.666 - tempB) * 6
        Else
            B = temp2
        End If
    End If
End If

R = R * 255
G = G * 255
B = B * 255


ReturnValue:
Select Case RGB

    Case "R"
        GetRGBFromHSL = Round(R, 0)

    Case "G"
        GetRGBFromHSL = Round(G, 0)

    Case "B"
        GetRGBFromHSL = Round(B, 0)

End Select

End Function

How to use the function:

The function contains 4 arguments.  The Hue degree, Saturation %, and Luminance %, plus the letter R, G or B depending on the value to be returned

RGB from HSL

The calculation for converting from HSL is based on the calculation from here: http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/

Convert from RGB to CMYK

The following UDF provides the % value for Cyan, Magenta, Yellow, or Black based on the RGB color codes.

Function GetCMYKFromRGB(Red As Integer, Green As Integer, Blue As Integer, _
    CMYK As String) As Double

Dim K As Double
Dim RedPct As Double
Dim GreenPct As Double
Dim BluePct As Double
Dim MaxRGB As Double

RedPct = Red / 255
GreenPct = Green / 255
BluePct = Blue / 255
MaxRGB = Application.WorksheetFunction.Max(RedPct, GreenPct, BluePct)

If MaxRGB = 0 And CMYK <> "K" Then
    GetCMYKFromRGB = 0
    Exit Function
End If


K = 1 - MaxRGB

Select Case CMYK

    Case "C"
        GetCMYKFromRGB = (1 - RedPct - K) / (1 - K)

    Case "M"
        GetCMYKFromRGB = (1 - GreenPct - K) / (1 - K)

    Case "Y"
        GetCMYKFromRGB = (1 - BluePct - K) / (1 - K)

    Case "K"
        GetCMYKFromRGB = K

End Select

End Function

How to use the function:

The function requires 4 arguments.  The R, G and B values, along with the letter C, M, Y or K, depending on the value to be returned.

CMYK from RGB

The calculation for converting to CMYK  is based on the calculation from here: https://www.easycalculation.com/colorconverter/cmyk-rgb-color-convertor.php

Convert from CMYK to RGB

To get the C, M, Y, or K percentages from RGB use the UDF below.

Function GetRGBFromCMYK(C As Double, M As Double, Y As Double, K As Double, _
    RGB As String) As Integer

Select Case RGB

    Case "R"
        GetRGBFromCMYK = 255 * (1 - K) * (1 - C)

    Case "G"
        GetRGBFromCMYK = 255 * (1 - K) * (1 - M)

    Case "B"
        GetRGBFromCMYK = 255 * (1 - K) * (1 - Y)

End Select

End Function

How to use the function:

The function requires 5 arguments.  The Cyan, Magenta, Yellow and Black percentages, plus the letter R, G or B, depending on the value to be returned.

RGB from CMYK

The calculation for converting from CMYK  is based on the calculation from here: https://stackoverflow.com/questions/10690125/coloring-cells-in-excel-with-cmyk-cell-values

Color conversion add-in

Using these conversion functions, I have created an Excel add-in that will quickly switch between the different color codes.

Get the add-in for free from the downloads section.  To install the add-in, follow the PDF instructions included in the download, or follow the instructions in this post.

Once installed, the EOTG menu will include an icon called Converter in the Color Codes group.

EOTG Ribbon with Color Converter Add-in

Click the button to open the tool.  When entering values into any of the boxes, the other boxes will automatically display the converted codes.

Color Code Converter Add-in User Form

Conclusion

I hope this post provides you with all the color conversions that you need.  If you want to convert between two methods that I have not covered above (for example, hex to HSL has not been included), convert from the source code to RGB, then from RGB to the target mode.

Now that you can convert between color codes, you should check out the following posts, which will help you along your Excel journey.

Don’t forget:

If you’ve found this post useful, or if you have a better approach, then please leave a comment below.

Do you need help adapting this to your needs?

I’m guessing the examples in this post didn’t exactly meet your situation.  We all use Excel differently, so it’s impossible to write a post that will meet everybody’s needs.  By taking the time to understand the techniques and principles in this post (and elsewhere on this site) you should be able to adapt it to your needs.

But, if you’re still struggling you should:

  1. Read other blogs, or watch YouTube videos on the same topic.  You will benefit much more by discovering your own solutions.
  2. Ask the ‘Excel Ninja’ in your office.  It’s amazing what things other people know.
  3. Ask a question in a forum like Mr Excel, or the Microsoft Answers Community.  Remember, the people on these forums are generally giving their time for free.  So take care to craft your question, make sure it’s clear and concise.  List all the things you’ve tried, and provide screenshots, code segments and example workbooks.
  4. Use Excel Rescue, who are my consultancy partner.   They help by providing solutions to smaller Excel problems.

Leave a Reply

Your email address will not be published. Required fields are marked *