Global (colour) variables I've found a few questions around this already, however none are quite satisfactory IMO.

Basically, my use case is to have


several materials on a quick switch panel for a number of objects to select theme variations - that works quite well with a custom operator that assigns the materials when triggered from the panel (if there's a better no-code solution I'm happy to look into that).
Those materials share (at least) one (base) colour that's globally settable, again e.g. from a panel. Now I could also add custom code for that I guess, updating all nodes for all affected materials when a new selection is picked, however,
the global colour value should also ideally be animateable, which is where the node-group trick doesn't work anymore (if I read that ticket correctly; outside of the shared node group the animation of course works again).


So, is there a better alternative than what I mentioned above already?  I had some trouble putting a colour as an object property - if that should actually work maybe you could point me to an example for it.
Start Blender from the console with the '--enable-new-depsgraph' parameter. The Nodegroup will work now.