>> Hc_label=uicontrol(gcf,'style','text',...
                      'position',[10 10 70 20],...
                      'string','Clormap:');
>> Hc_map=uicontrol(gcf,'style','text',...
                    'position',[80 10 60 20],...
                    'string','hsv',...
                    'callback','colormap(eval(get(Hc_map,''string'')))');