My buddy has the copaqs. I have trouble with them in low light. The diamonds (blue) and spades (black) look too similar in color and shape when peeking at your hole cards and I have 20/20 vision. I had to lift my cards all the way off the table a few times to verify suit.
I've always thought the green and blue were too dark to be of any use on the Copags. It sounds like the suits and colors are weird too on your friend's setup. I thought hearts:red spades:black clubs:green diamonds:blue was the accepted standard.
My favorite 4 color deck was the black/gold Modianos (I think?) from a CT group buy with a custom poker chip background.
Unfortunately my players that have trouble seeing don't like the four color copags. Diamonds and spades and clubs all appear black... According to them. Other players comment on four colors being odd. We continue to use jumbo 2color copags.
I have a set-up somewhere (unless I gave them away). They were given to me, and they are horrible. The green and blue are so washed out (in order that they are not mistaken for the spades, that they are ugly as hell.
I have some players who love the 4 colour decks and others who hate them. My biggest issue was that my Copags had 4 pips which I'm not a huge fan of, but I've just ordered some newer 2 pip replacements. The Modiano 4 colour decks are out of stock even at Brybelly at the moment.
I too Love my Copag 4, but I get a lot of comments from my players because they "DON'T UNDERSTAND" how to use them.....and none of them are color blind or too old for that matter. In fact one player I have likes them and He is the oldest one there.
I like four color on screens and in hand held card games, but not for any stud poker, including holdem. Any time you're peeking at hole cards, the lighting starts causing color problems for some people. Like that damn dress. Blue? White? Gold? Black?
If the four colors are bright and different enough to read as colors when peeking at holes, they look bad face up. Four colors that look good face up have peek problems. Doesn't happen with the classic colors, because we are forced to rely on the shape.