If NTSC50 is in effect you WILL get black and white picture on a standard NTSC TV.
Maybe the Amiga doesn't use this NTSC50, after all? (Or maybe you've got it backwards, and NTSC50 is wny the color is preserved?)
For as much as people have talked about color problems, I've never seen it happen, either. When you flip an Amiga to PAL mode, you get a color display with a different VHOLD setting. Some standard NTSC TVs are able to compensate (manual or overridable digital vhold), some aren't (most automatic vhold TVs). All that I've seen show a normally colored display, though (just for some, that display is rolling).
