"A grey that lives in the shadow of green" is how I would describe this colour I made by accident two nights ago. It's like a wet plaster colour. I think it came from looking at frescoes in Florence and Arezzo recently.
I have since learnt that there are two schools of thought when it comes to restoring frescoes. Years ago they would have tried to repair any damage in a way that is indistinguishable from the original, or as close to that as possible. The modern approach is to fix the damaged wall and colour it with these thin lines. Viewed from a distance the overall image is intact but when you get closer it is obvious which section was painted by the original artist and which has been added by the restorer. Any marks they add are removable.
The current phase of some of the canvases reminds me of this frescoesque juxtaposition of randomly shaped plaster stains scattered amongst highly coloured areas.