Adwaita-White Gnome Shell theme by deviantARTist Oberon27 blends nicely with Adwaita Theme and gives a consistent look for your all over Gnome 3 experience.
- Backup /usr/share/gnome-shell/theme folder
- Download Adwaita-White Gnome Shell theme from here
- Extract the archive and rename gnome-shell to theme
- Copy this folder to /usr/share/gnome-shell/
- Restart Gnome Shell by hitting Alt+F2, then type r and press enter