Tiles background in speed dial folders is really bad visible when light theme is enabled. With dark theme tiles background looking good.
Light:

Dark:

That's and previous build(x64 version, standalone instalation) doesn't launch. Showing black logo and next white small window, again black logo -> small white window and repeats thats few time and at end that launching process stoped without open browser(in task manager opera is not visible after that). Clean install doesn't help. Build 4906 and olders working fine. System is Win10 x64.