This game reminds me a lot of the commercial game Hue, but in that game, collision only works when colors are visible (also it works by only hiding the color selected, rather than showing). From a conceptual standpoint, this game actually is much more complete than that. By having it so that there are some platforms that are solid while invisible, some platforms that are solid only when that color is selected, and some platforms are only solid when not selected, it makes this game more mechanically diverse. I will say though that the game becomes really confusing and kind of frustrating to play when there becomes too many colors to pick from.
I do really like too that you go back to previous areas and reveal more secrets in them. As a lover of Metroidvania design, that was enjoyable.