Jeff, . I restored my fold-down seat panels including the trap door a few months back and I'm pretty sure the hinges are same color as panels and trap door - charcoal grey.
Rick
Thanks Rick will double check the original sets I have at the shop. Unfortunately the ones for my CJ were already stripped
Did check the picture collection and I would agree that the tone and coloration is the same as the trap door.
As always thanks for aiming us in the right direction - will alter the post above so no one gets mislead at a later date