By default, all uml element types are colored with a gradient background.

The gradient can be disabled (fortunately), but the is no simply possibilty to disable or reset the colors to a 
standard black/white color schema (i. e. for printing, export, etc.)

During design time the colors can be useful, but for documentation purposes the diagrams are a bit to colorful 
(=unprofessional).

Please provide an option to (simply) switch to a monochrome color schema - like other uml tools - or to select from a 
list of color schemas (i. e. like css media types).