Mrs. BD and I attended a lecture on Romanesque stone architecture at the Cloisters today. I've seen plenty of it in Europe and have read plenty about the style. I asked the expert whether the stone sculptures on lintels and columns in churches and cloisters had been painted.
Definitely, she said. Columns were painted in primary colors. The church walls, so often plain limestone now, had been stuccoed and then plastered with frescoes. Over 1000 years it flaked off.
I've seen reconstructions of the once-painted Greek sculpture and architecture. I'd like to see the same of Romanesque-era churches and cloisters.
Photo is from Pórtico da Gloria, Santiago Cathedral. The colouring once common to much Romanesque sculpture has been preserved - via Wiki