There's some code to get you started at:
http://www.tech-archive.net/Archive/.../msg00359.html
It should work with any Office application. As coded, the userform merely changes it's own background colour - you'd need to modify the line 'Me.BackColor = cc.rgbResult' to do whatever colouring you want for each application. to colour the selected text in Word, for example, you could use 'Selection.Font.Color = cc.rgbResult'.