I am sure others will disagree - but I personally do NOT like the lack of color in the UI!

My first reaction was that my computer was locked up -- like when windows 7 puts that haze across the whole screen when the computer is not responding...

Second reaction was -- what? did I accidentally install auto desk inventor?  all the blue looks very similar...

I find it difficult to see the difference between commands that are active & commands that are inactive. needs much more contrast!

The contrast between a plane that is hidden versus a plane that is visible within the feature tree is terrible!!!!   The Solidworks 2015 feature tree with the yellow and green - you could easily see the back ground color of the feature tree through the hidden plane.  But now in 2016 looks like the only way to tell the difference between visible and hidden, is to get your face about an inch away from the screen, squint, & you might be able to see that the hidden plane is lacking object lines around its border.  really!?

suppress versus unsupress is a little better than hidden versus visible - but not by much.  Yuck!

Darker colors are much better on my eyes -- now all I can see are the floaters in my eyeballs...  I have turned down the brightness on my monitor but does not seem to help.

I'm the guy in the office who helps people when they need assistance... Now I wont be able to say "grab the blue hoop on the manipulator triad"...  Or say some thing like "click on the square green selection filter icon"  & them know immediately what to do without me having to point with my finger...

Looks like the only colors left is the triad in the lower left corner, the rebuild icon, & the many appearance "beach ball" icons...

I hope I will get used to it, or at least find ways to tweak the interface colors through windows themes or  some 2016 setting I have not found yet -- but overall I am very disappointed by the lack of colors.

These are just my opinions -- what are yours?