I think it makes a difference, but not all the time. Sometimes crappie will hit any color that touches the water. Other times they turn up their noses at everything that doesn't match whatever color they've collectively decided to hit that day. Painted heads can help you find the right color combination. Say they are keying in on chartreuse and refusing everything else. If you tie on a pink and white jig with a chartreuse head, you'll get more hits than if you would on a pink and white jig with an unpainted head.