Abstract. Bright new comets offer an opportunity for tracing the evolution of their dust production along a large heliocentric distance intervals. We started observations of comet C/1999 S4 (LINEAR) in November, 1999 when its heliocentric distance, r was 3.8 AU. At this time we obtained images of the comet in 5 narrow-band spectral ranges. We derived the cometary flux in these images by synthetic aperture photometry around the nucleus. The fluxes show small reddening of the cometary dust, about 0.2 mag in the spectral range from 387 nm to 663 nm. Reddening of the dust is seen in the images obtained in February 2000 (r = 2.8 AU), and in March 2000 (r = 2.4 AU), also, but this effect is disturbed by increased contribution of gas emissions in some of the observed spectral intervals. We present images of the comet calibrated in terms of Afρ and a map of the dust colour derived from the two clean continuum windows at 443 nm and 684 nm.

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