Hi all,
In 1200 painting was not so diffuse in Florence and governor of city called some Greek painters to decorate some churches (see Vasari). There started to work Cimabue that learned to use verdaccio as an underpanting of flesh color.
Before apply verdaccio it did a line drawing and traced some dark area with terra verte (earth green) then on top
of it applied the verdaccio.

Cimabue taught the process to Giotto. Giotto taught the process to Taddeo Gaddi that was his pupil for 24 years.
Taddeo taught it to his son Agnolo. Agnolo taught it to Cennino Cennini that reported the process in his
Craftsman's Handbook.
http://www.noteaccess.com/Texts/Cennini/

No green pigment was used. Only black, yellow ochre, white and red. White in the english text is called white lime
but actual italian name was "Bianco San Giovanni" literally translated "White Saint John" but I do not think it exists any more. Yellow Ocrhe was available at that time in two versions: dark and light. Cennini wrote to prefer dark if possible. The red was cinabrese. So no green is present in the mixture. Also the recipes provided by
Wikipedia seems wrong because it does not cite the red.

I wrote an article on this here.
http://www.drawandpaint.net/verdaccio-underpainting/
Thank you