The blue glow in the dark style is definitely over powered in comparison to the rest of the dark style.
However the glow in the light theme is great though, subtle and sleek. In fact that green progress bar would probably look good with the same... err... actually, I couldn't help but have a fiddle with it while I was writing this, just to see what it might look like...
Its a pretty rough job I banged out in a few minutes so don't look too close.
I was just playing with the colour balance across the UI. The window title bar colours aren't quite right (still too bold I think) and the tick boxes above were just an experiment with similar styling.
I also would love to see some UI performance improvements as it does seem to have a bit of a hit when you start drawing a few UI elements. I'm pretty sure this has been talked about several times over the years though, so won't dredge it up again.
Very interesting update though. Look forward to how this turns out, and any GUI related improvements in the engine!