I just wanted here to cast a light on the specific SuperLumiNova system developed by MB for the Homage to Nicolas Rieussec.
It's made of SuperLumiNova (SLN) and I think pictures speak for themselves on how it works :
The SLN pigments are directely set inside the hybrid ceramic layer, which had never been done before - and they are of the same color of it. So, during the day, the numbers can't be seen at all.
On the 'pros' side : exclusive process, elegant, smart.
On the 'cons' side : maybe it would have been smart too to ad a small layer of SLN on the edge of the GMT hand as well. For now, when the light comes down, it completely disappears...