Although the fabric has been treated to be UV-resistant, it will discolour under the influence of UV radiation from the sun. This depends on the colour of the fabric and the extent to which the tent is exposed to UV radiation from the sun. Dark colours are more sensitive to this than light colours.
We therefore recommend that you do not expose the tent too intensively to UV light from the sun. Try to use the tent in a place where it is in the shade for part of the day.