This extremely thorough but super user-friendly online painting course will help you understand how to see and use colour, using the most respected colour system developed, the Munsell system. As Paul Foxton, teacher and artist, points out (quoting Graydon Parrish), painting is largely about putting the right colour in the right place. That, plus knowing how to draw and a having a good subject, should set you on the path to painting success. I’ve been doing this course myself and loving it. You also get to join his Facebook group where you can post your assignments and get helpful feedback. Highly recommended!