You beat me to it Janine! I was gonna post the link to this discussion from a while ago!
And within the silicone family, there are ones that are easy to remove, like amodimethicone. It is water soluble or the hard ones to emote like dimethicone. They can even melt into your hair, I
Especially if you use straighteners. There were many complaints about tresemme causing resistant to dye hair and when it was looked into it was straighter or hot iron use that had caused a plasticy layer on the outside hair shaft and was a total or partial barrier to hair dye penetration. There is a chart somewhere with a list of silicones, I will try and find it and post back if I do
Oh and boots do a very good clarifying shampoo it's boots own in a creamy coloured bottle with dark blue lid. Normally near the swimmers shampoos etc. ( also you could try chelating your hair, it's when a mineral or hard water build up is on your hair, that can lead to fading too, and if you clarify, you aren't chelating and vice-versa , they are two separate things, the swimmers shampoos are good at removing mineral build up and therefore are chelating)
My mom use to have my sister and I use a shampoo (I believe it was from the brand NEXXUS and it was green) after we had been swimming in chlorine, so that we wouldn't get a green look to our hair. I am pretty sure it was called aloe rid, it still left moisture in your hair unlike clarifying shampoos but it stripped out the mineral and chemical build up from the pool, that might be an option if you can find it. Its been so long since I used it though so I don't know if they still make it or what the ingredients are but it worked like a charm. I think Neutrogena makes a good one too but my hair definitely felt like straw afterwards, it left no moisture so if damage is a concern, I would stay away from that one.