I too think Motion/Movement sounds great. Between freezing it and emphasizing it, there's lots of room for creativity.
^ Agreed. My intent was to look for images that were dominated by any of the primary or additive colors. Not containing all three. That's way too tight.I'll go for movement also . While primary (or additive) colors are intriguing , finding subjects containing just the 3 might be too limiting.
^ I tossed out Color and Colorful several times in previous challenges. Where were you when I needed you? 🙂Movement has my vote as well. If it were up to me, I would change "primary colors" to "color" for broad and simple interpretation.