The invention provides a carpet back lighting system comprising a carpet back lighting unit having a lighting unit front face and a unit back face, wherein the lighting unit front face comprises a light source, arranged to generate light, and accompanying optics. The carpet back lighting system is suitable as back lighting at a carpet unit back side of a light transmissive carpet unit selected from the group consisting a carpet and a carpet tile. Further, the optics are suitable to be arranged to guide light into the light transmissive carpet unit, and wherein the optics are suitable to be arranged to penetrate into at least part of the light transmissive carpet unit.