Help for xgdisplay

Hi, I compiled XGRASS on USL UNIX SVR4.2 on PC486. When I run xgdisplay under
grass prompt, xgdisplay window shown up once and then crashed. The error maesgs

are as following:

        XGRASS DISPLAY LIB ERROR: Not enough colors available. Make more availab
available before starting again.

Does any one can tell me how to make more colors? I'm not fimilar with X window
environment yet.

                        PK Lin
                        E-mail: pklin@cerf.net
                        Tel: (617) 942-1655