Apparently the top search on this site is for “correct mix ratio silver sand nhl2 lime” .
I can answer that, There is no correct ratio but a good one would be between one and one and half portions of sand to one portion of NHL2.
did you know that there is no really discernible difference between Playpit sand, Silver sand and Kiln dried sand.
According to one of our guides in Naples red was the predominant colour used in the City as it was the colour of Pompeii. But this plaster shows the yellow gradually turning red. knowing that yellow ochre when heated sufficiently turns red and considering the heat that the plasters of Pompeii were subjected to, and with the evidence of this picture, I might suggest that Pompeii was Yellow rather than red.