While I was working on the Game Gear PNGs I noticed that three games (operating in SMS mode) had issues with the screen size and the colors scheme... I suppose the bugs are connected to the different video resolution and colors indexing between Master System and Game Gear (SMS 256x192px and 6 bit RGB palette, GG 160x144px and 12 bit RGB palette).
The "implicated" games are:
the Excellent Dizzy Collection (gg_excdizzy, gg_excdizzyp);
Street Hero (gg_shero, gg_sheroa);
Super Tetris (gg_stetris).
Attached two pics as example...