Yeah, annatto is a traditional cheese dye, but outside of the US cheddar doesn’t often have much annatto if any, so it’s not usually died orange. Here’s a video of someone making a marbled cheddar cheese where one part has annatto and the other doesn’t, so you can easily see the difference in the final product.
Biggest UK brand says just milk, starter culture, rennet and salt.
https://www.cathedralcity.co.uk/en/faqs
Yeah, annatto is a traditional cheese dye, but outside of the US cheddar doesn’t often have much annatto if any, so it’s not usually died orange. Here’s a video of someone making a marbled cheddar cheese where one part has annatto and the other doesn’t, so you can easily see the difference in the final product.