Abstract: The invention relates to a method of controlling a temporal variation of light emitted by an illumination system. The light emitted by the illumination system varies from light having a start color point (14) to light having a target color point (12). The start and target color point are defined in a first color space (XYZ, RGBvid, RGBill), which is perceptually non-uniform. The method according to the invention converts the start and target color point from the first color space to a second color space (Lab, Lch), which is more uniform to the human visual system than the first color space. The method further comprises a step of generating an intermediate color point (34, I1, , I2) located on a transition-path (p, p?) within the second color space, an intermediate distance (d) between the start color point in the second color space and the intermediate color point in the second color space not being larger than a threshold distance (26).