"These magnificent buildings retain their grandeur, but their walls, faded to plain gray stone, would have been unacceptable to mediaeval men. Sadly, the monochromy of surviving Gothic architecture has given many contemporary men the misconception that Gothic architecture is not supposed to be painted. A Gothic church in full color is difficult to find nowadays; those that exist are so striking as to be presumed exceptional." --Daniel Mitsui, who has posted photos of the High Gothic Amiens Cathedral, its facade bathed in spotlights and laser beams to give us a vivid jolt as to what such cathedrals would have actually looked like in their day.
Mitsui also has an earlier post on the Priory of St. Mary at Binham, in Norfolk. There was a rood screen and its panels were painted with holy images of Our Lord and His saints. Then reformers whitewashed them (typically they would just tear out the rood screen altogether), and over the whitewash they painted biblical texts (because the reformers were so fecund with creativity). Now some of the whitewash has been peeling off over time, revealing images of rather buoyant verve; images light and deep and alive, some of their colour still intact.
One wonders if the Protty whitewash inadvertently helped to preserve some of the images.
Be sure to go also to the Norfolk Churches website.