The Enchanted Cottage - S5.E21

Mary starts to be able to distinguish light from dark and the Ingalls believe she is regaining her sight. Mary is taken to the specialist only to discover that a brain impulse was causing her to see light when she felt the heat from the sun coming through a window. While Mary is away, Albert and Laura fix up Mr. Edwards' old home. However, the only colors of paint that the mercantile has is pink and purple. Mary returns and talks to Laura in the old Edwards' cabin. Laura tells Mary that her and Albert were building a club house. Mary tells Laura she is glad she can't see the room after Laura tells her what colors they used.