Thanks! Wash the figures with soap and water first or you'll risk your paint not holding. Then take some black acrylic paint (I got mine at Michaels) and a touch of water and paint over the knee and elbow pads and the bandannas. I tend to paint both knees and both elbows, then wipe it off with a rag or paper towel, and you're good to go.
On the headbands,I actually painted the eyes white first, waited for them to dry, then did the wash on the bandannas. After the wash dried, I brushed on a fresh coat of white so the eyes would stand out more.
I've said this before and I'll say it again: I am not the most artistic person you'll ever encounter. If I can do it, just about anyone can. Just take your time and keep a wet cloth or paper towel handy in case you need to quickly wipe up a mistake.