PAL games display in Black and White on my US console

Anyone why this happens? I have a brand new TV that isnt even a month old. It plays all PS2 games and any other console games from all regions in full colour. But for some reason, PAL games on my US Gamecube show up in Black and White. I tried changing the options on my Viper bios to PAL 50hz, PAL 60hz, etc but it doesnt make a difference.
BTW, I'm in the UK if that makes a difference.

Could anyone help me out, please?

 

The video forcing doesn't work on newer Cobra BIOS releases for some reason.

If you don't need to rip games any time soon, just flash GCoS to your ViperGC Extreme until they get around to fixing the problem.

 

I have a similiar problem too.Bu why that video forcing doesn't work

And please can you explain haow can I flash GCoS and what is that anyway?

 

It doesn't work because they ruined the coding somewhere along the line. I know it worked in earlier versions, but those aren't compatible with ViperGC Extreme.

GCoS is short for GameCube Operating System. Originally developed for soft modding, but has expanded to hard mods as well. I would assume that it's flashed the same way as the Cobra BIOS.