Some of my backup games run without colors:-(

[Smaugen]

Hello all!!!

I have a PAL version Playstation (chipped). I use a scartlead to my TV, but some of my games do not run with colors. Or we can say 2 colors, black and white. lol
What can this problem be ? Is there anything I need to get this games run in colors ? (Its more fun with colors)

I hope someone can solve this problem.