gravitone wrote:Nothing wrong with the discs. Bad data will result in the system hanging. Usually there is some crc error correction in place to prevent this from occuring. Since the bios is displaying just fine, and the problem is only with the color. And by color I assume the whole screen shows the wrong colors, I think we can conclude that the dreamcast is outputting colors in the wrong color format. i.e. its probably a PAL/NTSC problem. Try both a PAL and NTSC version of a game and see which one works fine. which type of cable are you using? It might be that your tv is forced to either PAL or NTSC instead of automatically detecting and selecting the right color system. It could also explain why your bios screen shows up fine and not your games if the bios is for example a PAL bios and all your games are NTSC.
Also note that a lot of the pirate releases have a PAL/NTSC switch. Make sure you are selecting the correct option for your region when you boot the game. If your in the USA selection NTSC/60hz, if in PAL land you'll want PAL/50hz