When I was a wee l'il lad
(age 5 or so) for my birthday I was given a He-Man colouring book
COMPLETE WITH REAL He-Man crayons
I guess some advertising executive somewhere decided that they could up the profit margin an extra 10% by going around the crayon wholesalers and vending their own, brand-named product (even though, in all truth, He-Man is not known for the success of their non-toy merchandise 8)...
They were for all practical purposes slightly sub-Crayola-par in terms of their utility, but all the colours had different, quasi-He-man-centric names! Like Planet Purple and Heroic Blue and Eternia Orange...
I don't think that galactic green was one of the names, but it certainly has the right feel to it.