Jax,
The color of the trunk spatter paint really depends on the build date and assembly plant. GM switched from a gray and white to an aqua and black splatter in mid year production of 66. The factories didn't waste anything, so whatever existing gray amd white was used up before using the new color. So a lot of 66 models got the aqua and black paint, which was used through 1972.
This has always been a bone of contention in national Chevelle shows. I have interior and trunk judges that I have to point out these same facts. They want to deduct points from a 66 with aqua/black trunk because they think that all 66s should have the gray/white splatter paint.
Also, the rattle can trunk paints that resto supply companies sell are too dark compared to the original splatter paint the factories used.