not all apps have multicolor gtkheaderbar in gtk 3.26 or gtk 3.28
Created by: denikris
ubuntu-budgie 18.04 lts budgie-desktop 10.5 (from backport ppa)
some apps like budgie desktop settings, gnome system monitor, gnome calendar and google chrome (chromium) have dynamic colors like grey/green/purple but some apps like file-roller, gnome-calculator and gedit have default blue like nautilus and non-csd apps
they are in version 3.28