Colour Cells using RGB values "Error 13" - excel

Question

Very simple vba problem, not sure where it is going wrong, but:
Range("J21").Select
For tastetherainbow = 1 To 1000
skittle = ActiveCell.Offset(0, 2).Value
Selection.Interior.Color = skittle
ActiveCell.Offset(1, 0).Select
Next
The cell containing each appropriate skittle value contains an RGB code in the form RGB(r,g,b) , exactly as it should be for the VBA. I have tested it by copy pasting the cell's value into Selection.Interior.Color = paste without issue, but I get a "type mismatch" when it just uses skittle.
In fact, the only reason I am using skittle as a variable is that I had the same issue when I used Selection.Offset(0,2).Value to set the colour.
Rather lost! Could you let me know how to fix it, and why I have this issue.
Thanks!

Answer 1

It's recommended not using Select , Selection and ActiveCell , instead I preffer to start the For loop from Cell "J21" and just advance the row by 1.
Code
Option Explicit
Sub CellColors()
Dim Skittle As Long
Dim tastetherainbow As Long
' modify "Sheet1" to your sheet's name
With Sheets("Sheet1")
For tastetherainbow = 1 To 1000
Skittle = .Cells(tastetherainbow + 20, "L").Value
.Cells(tastetherainbow + 20, "J").Interior.Color = Skittle
Next tastetherainbow
End With
End Sub
Edited Code: converts the cell string format of "RGB(0,0,74)" to 0,0,74, then using the Split function putting the Strings into 3 elements of an array.
Then calculating Skittle Long numeric value using CInt and the RGB method.
Option Explicit
Sub CellColors()
Dim Skittle As Long
Dim CellRGBStr As String
Dim RGBInd() As String
Dim tastetherainbow As Long
With Sheets("Sheet3")
For tastetherainbow = 1 To 1000
If .Cells(tastetherainbow + 20, "L").Value <> "" Then
' use a string to store the "RGB(0,0,74)" as 0,0,74
CellRGBStr = Mid(.Cells(tastetherainbow + 20, "L").Value, 6, Len(.Cells(tastetherainbow + 20, "L").Value) - 7)
' split the CellRGBStr to 3 array elements
RGBInd = Split(CellRGBStr, ",")
' calculate the value of Skittle (using the RGB method)
Skittle = (CInt(RGBInd(0))) ^ 3 + (CInt(RGBInd(1))) ^ 2 + (CInt(RGBInd(2))) ^ 1
.Cells(tastetherainbow + 20, "J").Interior.Color = Skittle
End If
Next tastetherainbow
End With
End Sub
Another way to calculate Skittle is with the RGB function:
Skittle = RGB(CInt(RGBInd(0)), CInt(RGBInd(1)), CInt(RGBInd(2)))

Answer 2

Thanks for all the help guys, I modified it and cheated a little... This is running as part of a much larger macro, so I decided to just make the array of R, G, and B values explicit, and do it this way. From reading online Victor it says that RGB() expects values as integers - Long is more efficient but does the same thing nowadays no? Here is a working version. Couldn't have done it without you both thank you very much!
Sub ColourMeImpressed()
Dim Skittler As Long
Dim Skittleg As Long
Dim Skittleb As Long
Dim tastetherainbow As Long
With Sheets("Converter")
For tastetherainbow = 21 To 1000
Skittler = .Cells(tastetherainbow, "G")
Skittleg = .Cells(tastetherainbow, "H")
Skittleb = .Cells(tastetherainbow, "I")
Skittle = RGB(Skittler, Skittleg, Skittleb)
.Cells(tastetherainbow, "J").Interior.Color = Skittle
Next tastetherainbow
End With
End Sub
For those interested, here is a screenshot of the final result:

Answer 3

'little modification is required in your code as follows
Range("J21").Select
For tastetherainbow = 1 To 1000
skittle = ActiveCell.Offset(0, 2).Value
Selection.Interior.Color = RGB(skittle)
ActiveCell.Offset(1, 0).Select
Next