rgbplot - displays the three components (red, green and blue) of a colormap
rgbplot helps visualise a colormap.
map1=sip_colormap('bluered'); // creates a 256 colormap
rgbplot(map1);
//have another try with:
map2=sip_colormap('bluegreenred');
rgbplot(map2);
http://siptoolbox.sourceforge.net