Can pearls be a warm off white color ?

by Elna
(Seymour, Ct.)

I have a very old pearl necklace and a newer one -- the new pearl necklace is white in color ( 40 years old) and the other pearl necklace is warm beige or off white color ( 60 years old ) - the older pearls have a soft luster if that makes sense - how do I find out what is natural or real ? Who can I bring them to? I can't upload a picture but can e-mail one if you like. Thank you.