Setting Cell Color Based on Numeric Values

Joseph uses regression to determine the result of color blending. He would love for a cell to be colored based on the RGB or HEX value data contained in a cell, but knows there is no way to do this. So, he ends up coloring cells manually. Most of his worksheets have many hundreds of colors, so this is very tedious. Joseph wonders if there is a way to automatically color a cell based on the RGB or HEX values contained in another cell.

Yes, this can be done using a macro. More appropriately, it can be done using an event handler which is a special type of macro that is run automatically based on an "event" that occurs within Excel. In this case you can create an event handler that is executed anytime something is changed in your worksheet, like this:

Private Sub Worksheet_Change(ByVal Target As Range)
    Range(A2).Interior.Color = CLng("&H" & Range("A1").Value)
End Sub

This macro should be placed in the code for the worksheet you want to affect, so right-click on the worksheet's tab and choose View Code from the resulting Context menu. You can then paste the code into the Code window you are shown.

This particular macro assumes that the desired hex value is in cell A1 and then changes the color in A2 based on that hex value. Using the macro will slow down your use of Excel a bit, as it is executed every single time something changes in the worksheet. If you prefer to change colors just by manually running the macro, you could use this variation, instead:

Sub SetColors()
    Dim rSource As Range
    Dim rTarget As Range
    Dim J As Integer

    Set rSource = Range("A1:A50")
    Set rTarget = Range("D1:D50")

    For J = 1 To rSource.Cells.Count
        rTarget.Cells(J).Interior.Color = CLng("&H" & rSource.Cells(J).Value)
    Next J
End Sub

When you run this macro, it looks at the range assigned to the rSource variable (A1:A50) and uses the values in that range to set the colors in the range assigned to the rTarget variable (D1:D50). Assuming you change the ranges assigned to both rSource and rTarget, you should make sure that both ranges contain the same number of cells.

So far the macros in this tip have relied on the source cell containing a hex value for the color desired. If you would rather work with individual RGB values for the cells, that has been covered in a different tip that you may find helpful.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (9963) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, and 2021.