In previous versions of Ubuntu (including Ubuntu 13.04) I was able to change the system ambiance colour from orange to a colour of my liking by using this in the terminal:
gsettings set org.gnome.desktop.interface gtk-color-scheme "selected_bg_color:#33B5E5;selected_fg_color:#FFFFFF"
This would ultimately change the orange ambiance colour to #3385E5 which is a blue colour.
Does anyone know how I can go about changing it once again in Ubuntu 13.10?
doug's answer is good but it's overkill. You can actually copy /usr/share/themes/Ambiance into your ~/.themes directory and then edit Ambiance just for your user.
My answer from Theme color conversion
A useful tool I use to customize gtk theme is gtk-theme-config. I for example like the default ambiance them but I set it to use a green scheme so it looks better with the gnome colors icon theme.
You can see here the greybird gtk theme wich has a blue scheme by default turned to purple and the gtk theme config at the bottom right corner.
Greybird gtk them wich has a blue scheme by default.
For install it in Saucy:
sudo apt-get install gtk-theme-config
For previous ubuntu releases:
sudo add-apt-repository ppa:shimmerproject/ppa sudo apt-get update sudo apt-get install gtk-theme-config
Source: http://www.webupd8.org/2012/09/customize-gtk3-gtk2-theme-colors-using.html
P.S. If you feel like it should be marked as duplicate, please go on.
That gsetting will now only affect a couple of areas, to get 'full coverage' you'll need to directly edit some files in /usr/share/themes/Ambiance/gtk-3.0
make your changes in settings.ini & gtk-main.css (maybe only one is needed, I do both
Also doesn't hurt to make same changes in /usr/share/themes/Ambiance/gtk-2.0/gtkrc though likely not needed if you've run the gsetting command
