Floor panels

1. A floor panel comprising:

at least a substrate and a top layer,

wherein the substrate comprises at least one first layer of a first thermoplastic material and a second layer of a second thermoplastic material,

wherein the second layer is adjacent to a first side of the first layer,

wherein the first layer is characterized by a first colour with luminance value L 1 in the HSL colour space and the second layer is characterized by a second colour with luminance value L 2 in a HSL (Hue Saturation Lightness) colour space and wherein L 1 is different from L 2 .

2. The floor panel according to claim 1 , wherein the absolute value of L 1 -L 2 is less than or equal to 50.

3. The floor panel according to claim 1 , wherein L 2 <L 1 .

4. The floor panel according to claim 1 , wherein the larger of L 1 and L 2 is less than or equal to 85.

5. The floor panel according to claim 1 , wherein the second layer is positioned under the first layer in the floor panel.

6. The floor panel according to claim 1 , wherein the first colour has a saturation value S 1 in the HSL colour space and the second layer has a saturation value S 2 in the HSL colour space, and where S 1 and S 2 are each less than or equal to 25.

7. The floor panel according to claim 1 , wherein a hue of the first colour is characterized by an angle H 1 in the HSL colour space and the hue of the second colour is characterized by an angle H 2 in the HSL colour space and where the smaller angle between H 1 and H 2 is less than or equal to 175°.

8. The floor panel according to claim 1 , wherein the thermoplastic material of the first layer is PVC, and wherein the thermoplastic material of the second layer is PVC.

9. The floor panel according to claim 1 , wherein the panel comprises one or more further layers of thermoplastic material that are only present on the second side of the first layer in the floor panel, wherein each of the one or more further layers of thermoplastic material is characterized individually by a luminance value Lx.

10. The floor panel according to claim 9 , wherein for each of the one or more layers the colour has a luminance value Lx that is different from L 1 .

11. The floor panel according to claim 9 , wherein for at least one of the one or more layers the colour has a luminance value Lx that is identical to L 2 .

12. The floor panel according to claim 9 , wherein each of the one or more further layers of thermoplastic material is characterized individually by a saturation value Sx, wherein each Sx is less than or equal to 25.

13. The floor panel according to claim 9 , wherein each of the one or more further layers of thermoplastic material is characterized individually by a hue with angle Hx, wherein the smaller angle between H 1 and each of the Hx is less than 175°.

14. The floor panel according to claim 9 , wherein the largest of L 1 , L 2 and all Lx is less than or equal to 85.

15. The floor panel according to claim 9 , wherein all of the one or more further layers of thermoplastic material are located between the second side of the first layer of thermoplastic material and the upper surface of the floor panel.

16. The floor panel according to claim 1 , wherein the top layer of the panel comprises a decorating layer, said decorating layer being located between the layers of thermoplastic material and the upper surface of the floor panel, wherein the decorating layer comprises a printed pattern.

17. The floor panel according to claim 16 , wherein the decorating layer comprises a thermoplastic film, wherein the film is provided with a decorative print.

18. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a vertical direction perpendicular to the surface of the panels, wherein at least one of the edges is provided with a groove, the deepest point is located in the first layer.

19. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a vertical direction perpendicular to the surface of the panels, wherein at least one of the edges is provided with a groove, the deepest point is located in the second layer.

20. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a horizontal direction in the surface of the panels and perpendicular to the edges, wherein at least one of the edges is provided with a hook-shaped locking part directed upwards, wherein the locking part extends at least partially into the first layer.

21. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a horizontal direction in the surface of the panels and perpendicular to the edges, wherein at least one of the edges is provided with a hook-shaped locking part directed upwards, wherein the locking part extends at least partially into the second layer.

22. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a vertical direction perpendicular to the surface of the panels, wherein at least one of the edges is provided with a groove, wherein this groove is flanked by an upper lip and a lower lip and wherein the upper surface of the lower lip is formed at least partially in the first layer.

23. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a vertical direction perpendicular to the surface of the panels, wherein at least one of the edges is provided with a groove, wherein this groove is flanked by an upper lip and a lower lip and wherein the lower surface of the upper lip is formed at least partially in the first layer.

24. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a vertical direction perpendicular to the surface of the panels, wherein at least one of the edges is provided with a groove, wherein this groove is flanked by an upper lip and a lower lip and wherein the lower surface of the upper lip is formed at least partially in the second layer.

25. The floor panel according to claim 1 , wherein the floor panel is arranged to, on at least two opposite edges, allow two such floor panels to be coupled together, wherein on the edges, locking is brought about at least in a vertical direction perpendicular to the surface of the panels, as well as in a horizontal direction in the surface of the floor panels and perpendicular to the edges in question, wherein the locking in the vertical direction is provided by at least one pair of interacting contact surfaces partly formed in the first layer, whereas the locking in the horizontal direction is provided by at least one pair of interacting contact surfaces partly formed in the second layer.