better default for get_color() without color setting

panda/src/pgraph/nodePath.cxx

@@ -1457,7 +1457,7 @@ get_color() const {
   pgraph_cat.warning()
     << "get_color() called on " << *this << " which has no color set.\n";
 
-  return Colorf(0.0f, 0.0f, 0.0f, 0.0f);
+  return Colorf(1.0f, 1.0f, 1.0f, 1.0f);
 }
 
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