  The V-K colours along the minor axes of spiral galaxies typically change from
red to blue with increasing distance, giving the impression that the near side
is systematically screened by dust. Such a preferred orientation for dust
screens is unlikely. Here we show that common extinction from the embedded dust
layer in an exponential disk has the same effect, making the near side
systematically redder as the inclination increases. The galaxy NGC 2841 is
modelled as an example, where the V-K profile is profoundly asymmetric and
actually step-like across the centre. We predict that the minor axis emission
profile of the same dust in the far-infrared, at wavelength 200 microns, will
be much more symmetric than the optical profiles, implying nearly equal column
densities of dust on both sides of the minor axis.
