Make sure that you have the same scene in your part/assembly template that you had in SW2012. I'm assuming that you have RealView enabled and latest graphic drivers.
In my experience, the cause of Dull Graphics can be the monitor or monitor settings.
Easiest way to check is to temporarily swap the monitor.
For example, look at the white menu color differences in this picture...
I was showing the difference in SW Desktops between SW2015 vs SW2016, however, the monitor on the right is an old Dell 25" monitor that is around 8 years old and on the left is a brand new Samsung S24C450 monitor.
Monitor was my first thought also.
If changing monitors doesn't help, It could also be a video driver setting.
Do other applications like Word or Excel look good?
Can you post a screen shot