On devices using OLED displays (or a variant thereof), right?,
I do vote for that, but I also want the coloured headers from Evernote Android app v4.x, as I hate the boring white interface of 5.x (hence me not upgrading to Android 8.x, and also why I don't use iOS), so I backed up the v4.x APK from my tablet, installed that on my phone for the time being, and disabled Play Store auto-updates on my tablet and phone.
So, if the developers listen, there could be 3 options in the app settings under "Theme" (not actual names of each option):
Boring white interface (a la iOS) (default)
Classic colourful interface (a la Evernote Android app v4.x)
The reason why I prefer the colourful interface, is because it allowed me to tell the difference between all notes, notebooks, and actual notes. (Tweet for context)