Thanks Michael.

I'm now using the call to moi.geometryDatabase.updateStaticFaceColors(); to force a refresh of the surface color in the viewport.
It works :)

Please, help me also with this last (for the moment) question:

Is there a way to programmatically set the current Lighting mode?

I mean, a way to programmatically mimic what we can find into the moi.ini settings:

LightingOptions={"selected":"Porcelain"...and so on...}

I ask this because I need to store in a backup variable the current Lighting mode, then set it to a custom Light that I created, named "Drat 2", the reset it back to its original moi's setting.

Is there an Api call to set that LightingOptions={"selected"} ?

Thanks.