[safety] Change colors of the GSN model elements figures
Make them look like the logical component elements. To modify the colors have a look here: org.fortiss.af3.safetycases.ui.DefaultStyle
The colors used for the logical components are to be found here: org.fortiss.af3.component.ui.DefaultStyle
(from redmine: issue id 2785, created on 2016-12-14, closed on 2017-02-13)