Noting that you have a Jap PS2 and are CloneCD compatible, have you tried using CloneCD to make a direct copy without patching?

Assuming you have a PAL z.o.e. and if there is no other protection for the game, then the Jap PS2 should play it and your PAL TV will show the game in colour. If you have an NTSC TV, it will play in B/W; if not then there could have been something wrong with the original.