Hey I made the Ubuntu Ambiance theme that ships with Blender.
I made a lot of tweaks over the years that never pushed upstream like fixing colors in the node editor and file explorer, etc. Recently I made some changes specifically for newer 2.8 stuff that is likely in flux. If you want my further vision of the theme on where it should be now for 2.8 you can download it here. This file may be updated due to 2.8 heavy development, but the link will stay the same, I’ll add a comment here whenever I update the file.
And here’s a picture, although for some reason the screenshot tool made the whole image get a weird greenish tint.
FYI:
I actually don’t use Ambiance as my theme in Linux anymore, although for Blender I’m still fond of this theme as I find it easy on the eyes and makes blender even more readable. I currenlty use the GTK theme adapta on my Ubuntu install and will hopefully be finished with my Blender theme “Nokto” soon which pairs well with Adapta Nokto GTK theme in Linux. I’m not sure whether it will be as good, but it’s getting better.