@@ -577,6 +577,9 @@ class XDotAttrParser:

             r, g, b = colorsys.hsv_to_rgb(h, s, v)

             a = 1.0

             return r, g, b, a

+        elif c1 == "[":

+            sys.stderr.write('warning: color gradients not supported yet\n')

+            return None

         else:

             return self.lookup_color(c)