Colors can be customized inside your class diagram.
From the menu bar select Window > Preferences
> eUML2 > Class Diagram > Colors.
Four options are available:
This preference allows you to choose the color of borders inside your diagram.
Eclipse presentation.
Eclipse presentation if Use of colors for borders is selected in the menu.
This preference allows you to put colors depending on Archetypes in your Class Diagram Editor .
For possibilities are provided :
This preference allows you to fill your diagram with gradient color.
Eclipse presentation.
Eclipse presentation if Use of colors for borders is selected in the menu.
This option is available only with "Eclipse presentation style"