A common symptom of eye cancer
is a white pupil in one or both eyes. This is called leucocoria and in children can be because of an eye tumor
. However, other color changes are not so significant in terms of cancer. Since you have seen this in a photo, i suggest you see his eye yourself in normal white light and see if you can make out any difference. If not then be rest assured, its nothing but a camera thing. If you do see a difference, there is no harm seeing an eye specialist. It may be something other than cancer.