I've taken the CB tests several times. When I was young (25-30) there was one panel I could not differentiate; all the rest were visible to me. By the time I went for my first FAA physical for a pilot's license, at about age 43, i had a lot of trouble with red-green. I had to go to a local airport and show them I could interpret the colors on a light gun from the tower. No problem with that - I can easily distinguish red from green in all but those picky tests.
So apparently this CB thing can change as your eyes age.
FWIW, I had cataracts removed a couple years ago; while colors became more intense, it did not improve the CB tests.