A structure (presumably unlockable with research) which strips paint off of shapes, returning them to neutral grey. The paint is destroyed but the shape remains. This would be handy for builds where you mass-paint shapes before they even get to your factory.
(There could also be a building which harvests only the color, or harvests both. Grinder, mulcher, disassembler, whatever you want to call it. The point is: reclaiming only part of a shape.)
Another use case would be to incentivise using the mixed-colour-but-otherwise-perfect-shape deposits, which lose purpose after getting painting, because you still need quite a few unpainted shapes, up until later when you will paint over them, due to the increased colour requirements.
Scarcity doesn’t seem like a design goal, so why not provide the player with more resources in the mid-game?
I agree. Having a station that strips paint off colored shapes would greatly enhance game play and allow colored shapes to be stripped of their color which would come in handy for a lot of the shapes in the tasks list. The pipes for this would run backwards, putting the stripped color back into the pipes of that color. Instead of being inputs, there would be outputs from the painter to connect up with color pipes of the same color. Basically it would be a color stripper that would be the opposite of the color sprayer.
Yes this would help a lot.

I agree with the paint stripper idea, which I posted elswhere. Some limitations on this feature would be that it breaks crystals, only works on the bottom (one layer) with no other layers on top, and ignores grey shapes and pinned shapes. Another limiation is that it would cost 100 points to unlock. This feature would be especially good for having more options when making shapes, or changning a current factory layout for buildings already in production.
I understand why the original post suggested the fluid be destroyed but I actually feel as though the fluid being saved and exported could also be a very interesting puzzle element. Just as an example, if you mine a red square corner and a green circle corner, you could use strippers to remove their paint and then direct them into opposite painters to get a green square and red circle, basically acting as a paint swapper.

Under Consideration after 2 years. Part of me wonders if a newer post is in order as it hasnt been resolved - but I say Paint Stripper as the main method of “removing” paint. Keep the “Uncoloured” paint as a debugging tool.


1.0 has uncolored paint

It’s not clear how this works in the game, if it has been added. I’ve tried looking up information related to uncolored paint for Shapez 2 and haven’t been able to find anything besides this post.
Edit: Someone noted under another thread how this is done in 1.0! See attached image. This should definitely be noted somewhere in the Codex or in the color mixer.