plotting continuos values in discrete colors

[Cicero Augusto Wollmane Zandona <cicero@xxxxxxxxxx>]

Hi,

I have some radar values (float) that vary from 0 to 200 and I've plotted
then using an Integer2DSet and mapping in RGB. The result is very fine.

But now I need to plot these values in a different way: They need to be
divided in intervals (like from 20 to 30), and each interval has it's own
RGB color (like 122, 255, 012). 

I don't know if I need to set different maps or something like that. I
would apreciate any help, sugestions or any example avalible.    

Thanks

CICERO