What you need:

• Stampin' Write Markers

How you do it:

If you're trying to get creative - one sure fire way is to ink a stamp with different colors, or emphasize a word in a sentiment with a different color.  To accomplish that, just use the stampin' write markers - they come in all the same coordinating colors as the cardstock.  Just use the larger brush end of the marker to color the rubber on the stamp.  If the ink dries before you get the image onto the cardstock, just breath on the rubber to remoisten the ink.