  In gravitational lensing the average colors of the images are not identical
to the average color of the source. The highly non-linear mapping of
gravitational lensing does not preserve the color balance of the source, and
this mapping is different for each image. The color distortion of the images is
illustrated using HST images of the lens SL2SJ02140. It is shown that in this
lens the color of the images is variable, reflecting the variable color of the
source. The average color of the images in SL2SJ02140 are interpreted as a
variable amplification of different sources regions with different colors. The
variation of the average image colors affects the measurements of the
photometric redshift of the images. This is especially true for SL2SJ02140
where the color variations due to the non-linear mapping of the lens simulates
pseudo redshifts variations.
