A Dutch photographer called Else Kramer gives online photography courses. I stumbled upon her website a while ago and she keeps her followers up to date with regular emails and social media posts. This November she initiated a 10 day color therapy 'course'. Every day the 'theme' was a different color take pictures of and if you so wished you could share them on a FB page.
I loved doing this! The results of my ten days can be found below (actually 11 as there was a purple bonus day in December)