A method and assembly produce color images of a scene captured by an image sensor exposed to visible light as well as IR radiation. A first image is captured with a first proportion of an iris aperture covered by an IR-cut filter. A first amount of radiation captured in the first image is determined and a second image captured with a second proportion of the iris covered by the IR-cut filter. A second amount of radiation captured in the second image is determined and a proportion of IR radiation is calculated in the scene based on the first amount of light, the second amount of light, the first IR-cut filter proportion, and the second IR-cut filter proportion. An IR contribution is removed from an image by using the calculated proportion of IR radiation.