All you need for this project is a pair of heels, rubbing alcohol, a bottle of white or cream nail polish and a bottle of nail polish in whatever color you want the soles of the heels to be. You will also need a couple of paint brushes and a plastic plate.
Use the rubbing alcohol to clean the entire sole of your shoe. You don't want to paint any dirt into the sole of your shoes. Then pour some of the white or cream nail polish on a plastic plate. Paint the entire sole of each shoe with the cream or white nail polish. Then let it dry completely (you can use a blow dryer to speed up the process).
Once the coat of white or cream nail polish is completely dry, paint the colored nail polish on the soles. You may need to do a few coats to make the color really pop. Again, let the coat of nail polish dry completely and you can use a blow dryer to help the paint dry faster.