Matching old Gel coat color, Blackman white

Took my cabin door hatch down to Fiberlay today to get a matching gel coat for doing some repairs. The salesperson said for me to take the hatch home and wet sand, then seal and wax it so I can get a real match. Question is: Is there a basic white that Blackman used for there boats. The person said Blackman got there paint from Velspar or Cruger, I think these were the companies. He thought he had the color chart for the Blackman boats but wanted me to try to get a more correct match if possible. Anybody ever buy white for their boats and what experience have you had with matching the correct color? Thanks for any help.

Still trying to verify correct color. Fiberlay got a color match but said they have to keep my hatch for a few days to insure they get a good match. They have to mix a batch, add pigment and then ck for color match. If not exact they will add some pigment to get closer to a exact match. Because my boat is a 1984 and the gelcoat was not kept waxed it cant be close to the original. Blackman may have used different gel coat colors over the years. My cousin is going to ask Steve for more info. He purchased the last Bill Fisher made by Blackman and has to do some modifications and needs some gel coat to match his boat. Still working on the matching thing.