gedit customisation via gsettings

I am trying to programmatically customise various settings in the gedit application, and currently I've got the following command to change the colour scheme.

gsettings set org.gnome.gedit.preferences.editor scheme 'cobalt'

The issue I have is, if you see below, there are some colour schemes which are two words. Now with that in mind, I've tried the following command, but with no success:

gsettings set org.gnome.gedit.preferences.editor scheme 'solarized dark'

Unfortunately, I do not get any errors or feedback to say the above command has not worked. Would anyone know what I have done wrong here?