The present disclosure generally relates to a method and device of encoding a color picture having color components (Ec) comprising obtaining (11) a luminance component (L) and two chrominance components (C1, C2) from the color picture to be encoded. The method for encoding a color picture having color components comprising obtaining at least one chrominance component from the color picture to be encoded, the method further comprises: —determining a first factor based on the value of each pixel (i) of said luminance component; —obtaining at least one final chrominance component by scaling said at least one chrominance component by said first factor; and—encoding (13) said at least one final chrominance component.