I forgot to mention, I modded my CD32 so that I have a PAL/NTSC (really 50/60hz) toggle switch. Most of the time I just left it in PAL.
I can find the details for that mod if you would like... It does not fix the problem - as still does not change the color frequency. It simply changes the default mode.
Yes, please find the source of your mod to switch between NTSC & PAL standards on your CD32 and share it with us. I assume it is different than using an early boot menu to switch between NTSC & PAL.