A rare color can affect a car's value. If you find someone who likes the color, it can add. If you can't find a buyer who likes the color, it can detract.

I don't think I would be too fond of a Primavera Beige Firebird...

I have a Goldenrod Yellow (uncommon), Coronado Gold (rare), and two Verdoro Green.

Chances of finding one of the rare colors in its original paint is not very high either.