This is called the Colorchallenge. For your topic just write Colorchallenge (Day) (color) . There is a topic for each as seen below.

Make Sure your First tag is #colorchallenge .

There is no winner or anything just a theme - But It is kind of fun - mostly i see photography but I think artwork would be fun to submit too for sure.

I don't generally use photoshop just the editing tools which are available on iPhone.