If you're on MAS 9.0 or higher, and have system administrator access, you can follow steps here: Updating the user interface - IBM Documentation
There are some things you can easily change such as logos, text for the environments, etc. and then there is the ability to override CSS to change the colors and such. This header example is in the documentation (though with a different color).
------------------------------
Steven Shull
Naviam
------------------------------