A floor panel including a top layer and a substrate, where the substrate at least one first layer of a first thermoplastic material and a second layer of a second thermoplastic material, where the second layer is adjacent to a first side of the first layer. The first layer is characterized by a first colour with luminance value L1 in the HSL colour space and the second layer is characterized by a second colour with luminance value L2 in the HSL colour space, where L1 is different from L2.