The frescos were revealed to be much brighter and more luminous when old re-painting was removed. In addition, the areas of middle ground are highly transparent, almost like watercolour.

It was evident that the painting in fresco was completed when the mortar and paint had dried, after which Giordano applied a layer of egg white that functioned as a transparent pigment to soften colours and tones, accentuate shadows and allow for nuances of detail.