1. A method of dynamic gamut control for a display ( 305 ) having a multi-spectrum backlight comprising a plurality of backlight sources (LR, LG, LB) with different spectra common for a plurality of pixels, the pixels of the plurality of pixels being formed by a group of sub-pixels, each sub-pixel corresponding to a transmission component (RF, RP, GF, GP BF, BP, WF, WP) illuminated by the multi-spectrum backlight, the transmission components for each pixel having particular transmission spectrums to provide a set of color primaries, wherein at least a first transmission component (WF, WP) of the transmission components has a transmission spectrum such that an intensity of at least one of the color primaries (PW) depends on an intensity of at least two of the plurality of light sources (LR, LG, LB), the method comprising determining a set of backlight intensities for the plurality of light sources (LR, LG, LB) by performing a sequence of iterations, each iteration comprising: for each of a set of color points of an image to be displayed determining ( 701 ) a color point backlight intensity set by for each backlight source (LR) of the plurality of backlight sources (LR, LG, LB) determining a minimum backlight intensity allowing a color of the color point to meet a representation criterion when backlight intensities of backlight sources (LG, LB) of the plurality of backlight sources other than the backlight source for which the minimum backlight intensity is determined are those of a set of backlight intensities determined in a previous iteration for the color point; and calculating ( 707 ) the set of backlight intensities for the current iteration by selecting backlight intensities for each of the plurality of backlight sources (LR, LG, LB) from the color point backlight intensity sets such that a number of color points for which the color point backlight intensity set comprise a backlight intensity above a corresponding selected backlight intensity is below a threshold.