Hello Jo Dean, and thank you for your question. Yes, the stair riser is made with frosted plexiglass and the area behind the
riser is painted white to help diffuse the light evenly throughout the
whole riser.

Typically what we would do these days is to specify a wet-rated LED strip or tape light under the tread nosing. In this case, the stair riser detail was constructed
pre-LED and the light source utilized here is a custom made
cold-cathode fixture. So there is no solar lighting or other spot lighting illuminating the stairs, it is simply the light just under the tread. We hope this helps, and good luck with your project.

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