The series of frescoes that Fra Angelico painted for the Dominican friars at San Marcos realise the advancements made by Masaccio and carry them further. Away from the constraints of wealthy clients and the limitations of panel painting, Fra Angelico was able to express his deep reverence for his God and his knowledge and love of humanity. The meditational frescoes in the cells of the convent have a quieting quality about them. They are humble works in simple colours. There is more mauvish-pink than there is red, and the brilliant and expensive blue is almost totally lacking. In its place is dull green and the black and white of Dominican robes. There is nothing lavish, nothing to distract from the spiritual experiences of the humble people who are depicted within the frescoes. Each one has the effect of bringing an incident of the life of Christ into the presence of the viewer. They are like windows into a parallel world. These frescoes remain a powerful witness to the piety of the man who created them.