Well I've figured out how the graphics are stored on the CG chips. Basically, they are using 4 bit planes to represent the colors, meaning this is a 256 color system.
I wrote a little C++ program to open the graphic roms and organize them a little better on screen so I could see them grouped properly. The colors are guessed at this point and I know there are 16 palettes to be used, so I just picked common colors and used 1 palette for this. Thats why the spades and clubs are red. The palette gets switched when the game is displaying cards.
I'm considering making this a real graphics editor sometime. It would be nice to change the card backs and animation pictures, etc. and burn new chips to put in my real machine. But for now I won't be adding any other features to this viewer.