Sub ChangeFontColor()
' This will change the color of all PowerPoint text to the color you specify in RGB below
' It won't affect text in charts, pasted graphics, groups, etc.

Dim R As Integer
Dim G As Integer
Dim B As Integer

R = Val(InputBox("Please input red value"))
G = Val(InputBox("Please input green value"))
B = Val(InputBox("Please input blue value"))

Dim oSld As Slide
Dim oShp As Shape
Dim oShapes As Shapes

For Each oSld In ActivePresentation.Slides
    Set oShapes = oSld.Shapes
    For Each oShp In oShapes
        If oShp.HasTextFrame Then
            If oShp.TextFrame.HasText Then
                oShp.TextFrame.TextRange.Font.Color.RGB = RGB(R, G, B)
            End If
        End If
    Next oShp
Next oSld

End Sub