Answer:
The color green is used as an under layer when painting faces.
Step-by-step explanation:
Terra Verte is the designation applied to a set of pigments that owe their color to green clay minerals such as celadonite, glauconite and chlorite.
In the Middle Ages it was widely used in tempera painting, especially in a layer underlying the carnation layer. Cennino Cennini describes this use as follows: 'pick up a little green soil and a little lead white, well mixed; apply two layers under the face, under the hands, under the feet and under the carnation areas'; When applying the pink colored layers, 'keep in mind that in wood painting more layers have to be applied than in mural painting; but not many more, so that some of the green that is already under the carnation areas is still visible ยป