I was playing with some puzzle ideas this morning, one of which involved messing about with different colours in a way which might be impossible for someone colour-blind. I won't go into details (spoilers!), but instead will make this a general question:
Is it OK to post puzzles which require distinguishing fairly similar colours in order to be solved?
For instance, let's say one step in the solution involves looking at a bunch of objects which are almost all of the same green colour and selecting those which are a slightly lighter shade of green in order to find some hidden message. This would probably not be doable by someone who's colour-blind.
I'm sure I remember seeing puzzles here which do involve this sort of thing, but I couldn't think of any off-hand. On the other hand, I've also seen at least one recent puzzle which underwent several edits just in order to make it easier for colour-blind solvers, so I thought it was worth a meta for this.
On the one hand, obviously we want to discriminate as little as possible. On the other hand, we have a lot of puzzles which would be completely unsolvable for, say, blind people, and I doubt anyone would call for abolishing the visual tag just for that reason. Does it make a difference that one of our active users (I don't recall who) is colour-blind, while as far as I know none of us are blind? Would it solve the problem to simply create a colours tag which colour-blind users could put on their ignore list, in the same way as a hypothetical blind user could ignore the visual tag?