Really neat concept of spattering your paint onto platforms to use them! I also enjoyed the level design in the last few levels, where you're more creatively making decisions on whether or not to use the paint.
I'm not sure about the gotcha platforms as a concept though -- those where you're tricked into using the paint on the wrong platform and then you don't have any left for the one you actually need. Specifically, because the amount of paint you have left doesn't restore after respawning at a checkpoint, the checkpoints begin to lose a bit of their meaning. I guess the idea is to encourage you to test out routes before you commit to a paint? Though then the level design just has to be careful about showing you when there are alternative paths. E.g. if there is a platform and you can't see what's below it, you don't know that this is a place to test paths. Or if the two paths are long enough that you need to commit to each to see if it leads somewhere, it's not going to work.
(I'd even think about removing the limit of paints available to the player and focus on the "can't fall through" mechanic for the level design. But that might be too limiting in terms of what you were trying to do with this game?)
From a more technical point of view, the paint explosion animation seems to suggest that the paint will rain down on any platform under it, but there is a short-ish range to it, which made me miss a platform. Also, having some more time to see the results of the explosion would be good.
This turned into quite the essay, but the points I'm making isn't that big; overall, this is a fun game with a really clever mechanic. Well done!