In the previous 28-pack poster offer write-up there had been mention of a Color M.U.S.C.L.E. poster that was completely devoid of any Flesh M.U.S.C.L.E. figures.
The inclusion of a Color poster was based on threads from LRG.com and testimonies of respected collectors. Without a physical copy or authenticated picture the Color poster can no longer be mentioned as one of the available posters.
It is widely accepted that the first M.U.S.C.L.E. figures reached retail shelves in late 1985. It is also believed that those first packages of 4-packs and 28-packs did not have the poster offer. The poster offer likely appeared after the first production wave, likely on the packages of orders placed once M.U.S.C.L.E. appeared in the 1986 Mattel catalog. The poster offer expired at the end of 1986 and disappeared from packaging after the Flesh figures were fully discontinued and Color figures were fully integrated.
It appears that Mattel honored requests postmarked by January 15th, 1987, which would have been at the time of full Color figure integration. Using this data and recognizing the three versions of the poster (Flesh, Flesh & Color, Color) it seems that Mattel initially sent out the Flesh posters. As the 50/50 Flesh and Color packages started shipping the Flesh poster was likely replaced with the Flesh & Color version. This also could have been because the initial printing of posters had been exhausted.
The 1987 release of M.U.S.C.L.E. was exclusively Color figures and did not include the poster offer. This suggests that the Color version of the poster was likely sent out at the very end of the promotion. Again, this could have been because the initial printing of the Flesh & Color posters had been exhausted.
It should not be inferred that the Color poster was only sent out during the 15-day 1987-window, but rather as Mattel decided the Flesh figures would be discontinued and replaced entirely by Color figures. For further information on the M.U.S.C.L.E. posters, please look to Advertising & Promotion 100.
The University of M.U.S.C.L.E. apologizes for any inconvenience or confusion this may have caused. This mix-up only strengthens the need for all M.U.S.C.L.E. data to be organized and centralized in one location.
If you have physical evidence that disputes this conclusion, then please email the University of M.U.S.C.L.E..