Assign the librefs and set the graphics environment. COLORS= specifies the colors list. By default the map uses the first color in the list.
libname reflib 'SAS-data-library';
libname maps 'SAS-data-library';
goptions reset=global gunit=pct border cback=white
         colors=(black blue green red)
         ftext=swiss htitle=6 htext=3;