For text:
[RangeObject].Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
For cell background
[RangeObject].Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
For text:
[RangeObject].Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
For cell background
[RangeObject].Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);