Hi,
I have the same problem since last two updates (7.3.23 and 7.3.30) on my mi5s. Bar is getting dark on home screen and any applications. Theme changing helps just for a while, Wipe Cache and Dalvik doesn't halp, factory reset (with data delete) helps only for while (one or two days).
Does anyone know how to resolve that problem? What's the reason of this issue?