Orpiment is a yellow color and is brought from Mount Gilboa; for this mountain is yellow on one side and green on the other, and so both green and yellow colours are found in it. There is also another yellow of a different shade, called ochre, and it is found in many places; but that which is brought from the city of Tours is more desirable than the others. Also there is another yellow colour, called saffron, and it is brought from Spain.