A fellow named Trimble posted quite a discussion on the C.I.T.A. chips, a B chip, and the Sphinx chips. He asked the same question about "who is P. Pearl".

Post has an ad announcing opening of Cal Neva Lodge in June 1941. Notice the chips were delivered a month before that, and the three colors in question returned about 10 months later (about the time a lot of guys were volunteering or getting drafted for WW2).

http://www.marlowcasinochips.com/links/genetrimble/illegaloftheday/BonesRemmerCA.pdf

Good thing Spragg has this big databasse to keep track of all the Illegal of the Week posts . Doesn't really answer the question at hand, though:

Why were the colors of the roulette chips that have shown up in the hobby so far the colors that were returned and sent to P. Pearl (address unknown)?