Rather than losing colour, it looks more like a build up, which could potentially be cleaned up? Have you tried something like BarKeeper's Friend somewhere in conspicuous to begin with? I don't know if bleach is advised for that particular surface material but that may be another option?

A good clean may help, as K OB suggestions. I would try Cif.

Tried all sorts of cleaning materials. When it first started we contacted the company who makes it and fobbed us off to the seller and then gave us the option of a new work top or a refund - which jus states there is a fault with the actual product

That worktop is solid surface. No cleaning products will take that back to when you purchased it colour wise. Solid surface finishes work differently to laminate.

You need to sand it back starting at 80 grit using a sander with a oscillating disc not by hand. Then work your way down from 80 to 120 to 240, 400, 500 and 600 if it isn’t changing colour.

You need all the different grits to work it down. That’s the only chance you have of getting the colour back. You have around 5-6mm of thickness to work with and then you are back to chipboard.

Sorry to be the bearer of bad news but I'm afraid this type of work surface and the other brand names of essentially the same thing are know to fade over time. I would personally take the refund and get something better like quartz or an ultra compact work surfaces instead. Best of luck , super annoying, feel for you :-(

Yea took the refund 7 years ago 😂😂😂 jus trying to find a way around it. Was thinking of painting it as tried sanding. There are a lot of options of paint jus trying to find the most durable one which will have a decent durability time frame

I doubt paint would be hardwearing enough. My sister had her worktop wrapped and she’s really pleased with it. There are different levels of durability but they are expected to last about 10 years.