You mischaracterized the situation; the baseline for a colorblind audience is legibility, not quality. In other words, you make it so they can see the difference, but not the beauty, which would actually be impossible. Also, there are many different forms of colorblindness which in toto add up to 10%, however, there is not, iirc, one case which the entire colorblind audience would see as one.

Actually, once this was put out in the open, and discussed, I was allowed to sign off on the artwork, and the project was completed successfully.