color pallet

I'm coding up a routine to dispaly a stacked bar graph using
Graphics2D. Each bar is made by a bunch of rectangles representing
each contributor. The color of each contributor should be different.

I need a way to assign these colors. The number of contributors can
change at runtime. Sequential colors should be well differentiated.

Does anyone have any suggestions for accomplishing this? I'd rather
not make the user specify colors at runtime.

Thanks,

Rob

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