I just found a small issue with the app.
I'm using red as my accent color in Windows 10 10586.
In the "classic" 1P app it show's red in the titlebar, in the universal one it shows in standart blue.
See these screenshots:
1Password Version: 1Password Alpha 1.1511.190
Extension Version: Not Provided
OS Version: Windows 10 (10586)
Sync Type: Dropbox (.opvault)