Q&A for How to Paint Leather

Yes, there is a paint by SEM called classic coat flexible coating. It changes or renews color on leather. Just spray it on, let it dry and done. If you have very soft leather it will not chip, crack, get hard and it comes in different shades in case you want to change the color of the leather.

Allow the fabric paint to dry for a day or two before touching, and at least 72 hours before washing. Always wash your painted garments inside out on a gentle cycle. Using warm water may help the paint not to crack.

Yes, but you may need to sand it down again beforehand to make sure the paint can still properly grip onto the leather.

The fact you're using multiple colors doesn't really matter, just paint on your design and follow the steps above--use acrylic leather paint rather than regular acrylic paint. Then, paint your design on and reapply every 30 minutes until the colors are solid. Allow at least 72 hours for your design to dry.