Because we needed a new improved and very different color encoding space for being able to faithfully encode the presently emerging high dynamic range video for good quality rendering on emerging HDR displays such as the SIM2 display, we present around that new color space various new decoders which allow simplified processing, in particular the handling of all achromatic direction (i.e. luminance) optimization separate from the chromatic processing, and increased quality of the reconstructed HDR images. This is realized by a video decoder (350) having an input (358) for receiving a video signal (S_im) transmitted over a video transmission system or received on a video storage product, in which pixel colors are encoded with an achromatic luma (Y′) coordinate and two chromaticity coordinates (u″,v″), the video decoder comprising a scaling unit (356) arranged to transform the chromaticity colors into a luminance-dependent chrominance color representation, by scaling with the achromatic luma.