excel automatically change the fill color based on a hex value in the cell code example
Example: excel vba highlight cells using the hex color value within the cells
'VBA function to color cells in selected range based on the hex
'color number entered in each cell. For example, #FF69B4
Sub ColorCellsByHex()
Dim r
If TypeName(Selection) <> "Range" Then Exit Sub
For Each r In Selection
r.Interior.Color = Abs(("&H" & Mid(r, 6, 2) & Mid(r, 4, 2) & Mid(r, 2, 2)))
Next
End Sub