Okay, this is a very simple example of how I do PAL vs NTSC colors in a bB project. I use descriptive color names like "mountain_color" and "flower_color", and use these contants in my code instead of setting colors by number. At the top I have two sets of these constants with the same names: one set for NTSC colors, and one set for PAL colors. I uncomment the version I am compiling for, and comment the other set. In the code below, the NTSC color constants are uncommented, and the PAL ones are commented, so it will build with NTSC colors. If you reverse those, then it will compile with PAL colors.
palntsc.bas