From the CRG files: http://www.camaros.org/exterior.shtml#BlackoutPaint
Q: Is it true that black-out paint was applied by the factory, and if so, for what models?
A: Certain first-generation Camaro models had semi-gloss black-out paint applied to the body to influence the appearance. There were two types, a "ground-effect" black-out applied to the rocker-panel/body-sill area for certain exterior trim options, and a blacked-out tailpan applied to SS-396 cars.
Body sill black-out paint was applied to Z22 cars in 1967 and 1968, and to Z21, Z22, and COPO 9560/9561 cars in 1969. But there were several body colors that were simply just too dark for this paint scheme to be effective, and for these colors (more below) the body sill black-out paint was omitted. Additionally, the body sill black-out was omitted for special models like the 1969 Z11 Indy Pace Car convertible trim package and the 1969 Z10 coupe trim package. A Chevrolet Product Bulletin dated 2-4-69 describes the Z11 (Pace Car trim package) package and includes this instruction: "Body sill to be painted white instead of black." Although no instructions have been found for the Z10 coupe, it would be natural for this same philosophy to have been followed.
There was also a paint color exception for the SS-396 tailpan black-out, but as far as we can tell, it was limited to black vehicles; in other words, only black (and special models like Z11 and Z10) SS-396 cars did not receive the (semi-gloss) blacked-out tailpans.
The CRG will continue to follow this topic and provide more detail with better substantiation as the information becomes available.
The 1967 and 1969 body sill paint codes that did not receive black-out paint (supported by GM documentation - except see note on 1969 #10 Tuxedo Black) are:
1967/1969 Body Sill Color Exceptions
AA Tuxedo Black
EE Deepwater (Dark) Blue
LL Tahoe Turquoise
MM Royal Plum
NN Madeira Maroon
10 Tuxedo Black*
51 Dusk (Dark) Blue
57 Fathom (Dark) Green
61 Burnished (Dark) Brown
67 Burgundy (Maroon)
* We have not found GM documentation
for the 1969 Tuxedo Black body sill
exception. However we believe it
followed the pattern of previous years,
and the few original 1969 cars we
have found appear to bear this out.