So far here are the main colors and stats for most of the pcengin systems.
PCEngine Duo - Black with purple button and matching two button controller
Turbo Duo - Black with black button and matching two button controller
Duo R - Off white with white button and matching two button controller
Duo RX - Off white with purple button and matching six button controller
CoreGrafx - Dark grey with blue writing and matching controller
CoreGrafx II - Light grey with orange writing and matching controller
PCEngine LT - Light grey with orange writing and matching controller
PCEngine - White with red writing and matching non-turbo controller
SuperGrafx - Dark grey with blue writing and matching controller
TurboGrafx - Black with yellow,orange logo and matching controller
Spain TurboGrafx - Grey with red, blue logo and matching controller
Thats all i could think of right now.
infUsiOn...