This is a question which is highly discussed on the internet but I've been researching for a long time and I've never found any scientific proof backing this up.

It's known (or at least spoken of) that intense light creates an effect called Photo-Synthesis, which makes colors like red fade away and turns white into yellow or brown, as can be seen on many items from our daily life.

Every museum containing ancient art forbids the use of Flash when taking photographs or even forbids photographs at all but some people claim this is just a rumour or an habit that has been passed down from generation to generation of museum keepers.

So is it true that flash hurts art or is it only a myth? Scientific backup is much appreciated in this discussion.