Just to disabuse you fellows, PCX files DO support 24-bit colors. It's just that FS doesn't support loading 24-bit PCXes.
If someone wants to change that, it's pretty simple, though.
24-bit PCXes store first all the red values of pixels, then all the green values, and then (surprise) the blue values. Actually, it's just like 3 8-bit PCXes one after teh other, except that there's only a header in the beginning, and there's no palette at all. You can tell if it's a 24-bit image in two ways by the header. Firstly is BPP, which should be 3, and as a failsafe, NPlanes should be set to 3 also. After decompression you should have something like three arrays, say, red[], green[], blue[], and then you should do something like image= rgb(red,green,blue);