Code:
Public Sub SetForeColor(Optional lForeColor As ColorConstants = vbBlack)
Dim tCharFormat As CHARFORMAT2
        With tCharFormat
            .cbSize = LenB(tCharFormat): .crTextColor = lForeColor: .dwMask = CFM_COLOR
        End With
        SendMessage RTB.hWnd, EM_SETCHARFORMAT, SCF_ALL, VarPtr(tCharFormat)
End Sub