How to get rid of Windows 10 optimized Firefox theme?

[anon(9226130)]

My firefox was updated to 40. And I used te colored titlebar theme, and the new update was f*cked up my Firefox's titlebar! IT'S THE ANNOYING WHITE!! How I can get back my old theme that supports the Colored titlebar theme and looks like in 8.1??? Sorry for tha bad words, but it is ANNOYING!!!!!

 

[mjperry51]

Roll back to 39.03 if you can find it. . .