I play regularly with a guy who's color blind, he has no problem. He does prefer to throw white discs though. But as he says, color has little to nothing to do with finding discs. Just look for a circular piece of plastic.
This logic seems faulty.
For example, there is a large white circle underneath this paragraph. It is hidden among the white background. If the colors do not matter, as per the above quote, then you should have no problem identifying it among the white background, since it is circular.
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