lookup_color
Description:
Looks up and resolves a color name in the this color map.
Parameters:
| this | |
| color_name | color name to lookup | 
| color | Return location for the looked up color | 
Returns:
| true if  | 
Looks up and resolves a color name in the this color map.
| this | |
| color_name | color name to lookup | 
| color | Return location for the looked up color | 
| true if  |