Believe it. Functions don't do formatting...

This can be done using an event macro. Put something like this in your
worksheet code module:

Private Sub Worksheet_Calculate()
Dim nFirstCellChars As Long
On Error GoTo ErrHandler
Application.EnableEvents = False
With Range("A1:C1")
.Item(3).Value = .Item(1).Text & .Item(2).Text
nFirstCellChars = Len(.Item(1).Text)
.Item(3).Characters(1, nFirstCellChars).Font.ColorIndex = _
IIf(.Item(1).Font.ColorIndex = xlColorIndexAutomatic, _
3, .Item(1).Font.ColorIndex)
.Item(3).Characters(nFirstCellChars + 1).Font.ColorIndex = _
IIf(.Item(2).Font.ColorIndex = xlColorIndexAutomatic, _
5, .Item(2).Font.ColorIndex)
End With
ErrHandler:
Application.EnableEvents = True
End Sub

The downside of this is that changing the font color of a cell doesn't
fire an event so you'd need to recalc the sheet in order for changes to
take place.



In article ,
1scant wrote:

After looking at a lot of threads, I find it hard to believe that this
cannot be done in Excel or VBA. However, I have seen the comments that
say that concatenate only works on values. I have to ask
anyway.

I want to CONCATENATE(SetColor(A1,red),SetColor(B1,blue)), where
SetColor is a function to set the color of that part of the
concatenation. Else, if I set the font colors of columns A and B, that
the concatenation in column C would retain the colors of A and B.