Ah... that's because I dropped colorscheme support in the latest upgrade. Not sure whether to just delete these alternative schemes or re-instate color aware windows decorations. TBH, completely forgotten about this one ;)

Was actually wondering how the titlebars got coloured while trying this out along with the other alternate colour schemes.

Totally forgot about this. Just posted Commonality Sol. Think I need to delete this.

And to actually answer this, the Aurorae elements use the usual 'class=ColorScheme-*' but whether by design or not, Aurorae follows the 'colors' file in the desktoptheme if it exists. In this particular case, titlebar color is View -> Hover.

(A few minutes later) Looks like the whole global theme would need to be re-made using these colors.