Index: src/unix/sdl_glimp.c
===================================================================
--- src/unix/sdl_glimp.c        (revision 802)
+++ src/unix/sdl_glimp.c        (working copy)
@@ -651,6 +651,7 @@
         tstencilbits = 0;
     }

+    sdlcolorbits = 4;
     if (tcolorbits == 24)
         sdlcolorbits = 8;