• Gnome 계열에서 사용하는 애플리케이션 GUI Toolkit
• https://wiki.archlinux.org/index.php/GTK

• https://askubuntu.com/questions/262868/how-to-set-icons-and-theme-from-terminal

#Change GTK-Theme:
gsettings set org.gnome.desktop.interface gtk-theme "CoolestThemeOnEarth"
 
#Change Icon-Theme:
gsettings set org.gnome.desktop.interface icon-theme 'MyIconTheme'
 
#Change Window-Theme:
gsettings set org.gnome.desktop.wm.preferences theme "CoolestThemeOnEarth"

• GTK - ArchWiki
• GTK 2 ~/.gtkrc-2.0

gtk-icon-theme-name = "Adwaita"
gtk-theme-name = "Adwaita"
gtk-font-name = "DejaVu Sans 11"

• GTK 3 $XDG_CONFIG_HOME/gtk-3.0/settings.ini (보통은 ~/.config/gtk-3.0/settings.ini)

[Settings]
gtk-icon-theme-name = Adwaita
gtk-theme-name = Adwaita
gtk-font-name = DejaVu Sans 11

• unity - Can I apply a different GTK3 theme from the main one to an individual application? - Ask Ubuntu
• GTK_THEME 환경변수로 임시 지정 가능함.

# gtk2
GTK2_RC_FILES=/usr/share/themes/Raleigh/gtk-2.0/gtkrc gimp
 
# gtk3
GTK_THEME=elementary pantheon-files