Both transmit about 45% of the incident light. The differences are in the absorption or reflection of the light and the scattering of the light. TUFTEX PolyCarb Smoke panels partially absorb the incident light to reduce the light transmission. TUFTEX PolyCarb Translucent White panels partially reflect and scatter the incident light to reduce the light transmission. The TUFTEX PolyCarb Smoke panels will absorb light and become warmer than the TUFTEX PolyCarb Translucent White panels when exposed to direct sunlight. For this reason, the TUFTEX PolyCarb Translucent White panels are a better choice when used for roofing on a sunroom or porch.