Ok - I understand what you're saying. You've applied an NTSC-PAL software patch. I could never get those to work (others have been successful). I was referring to a hardware device that sits between the PS2 and your PAL TV.
If you search the forum, there's talk of the PS1 Scart lead solving colour problems; although some people are very definite about it, I couldn't make that work - but I have a Jap PS2. Certainly worth a try though.

I solved all my problems (with the symptoms you described) by buying this convertor from Maplins. Why not take the PS2 down to them and see if it solves the problem? Or buy the gadget on sale or return. It will need the other type of PS2 lead - the TV end is red/yellow/white for the AV jacks.

When any PS2 plays a PAL game it puts out PAL to the TV; when it plays an NTSC game, it puts NTSC out to the TV. As you know, only a chipped PS2 can get to the point of playing an import (backup). So if it's playing in near greyscale, there is a video modulation problem. A video modulation problem is usually sorted out in one of the ways described above. I can't think of any way that the CD rip could have been gemerated in any way that turns colour information to near greyscale.

Good luck again.