Red is fine for VC paper. It should work fine with most/all VC papers. OTOH some of the Eastern European papers had trouble with lighter filters IIRC. But then I like red -)
As Nick says, I think the red will work OK for you. I know here in the US, online stores like B&H carry the filters. I also know when you see the price, you may decide you really like red!
Back in May, in need of a second unit, I got two -- with OC filters -- in decent shape off Eprey for a total of $39 including shipping costs. B&H currently lists the filters for $31.50 each!
Before buying new filters, consider using LED bulbs instead. I've got Dead Link Removed in a safelight housing without the filter, and it works quite well. I've heard of people using the amber LED bulbs, too, but I have no personal experience with this. The LED bulbs are likely to be less expensive than new safelight filters. Unfortunately, though, I can't point you to UK suppliers.
I find amber light so much easier to work with, so it would be good to find filters.
B & H was the only supplier I could find online. I don't mind buying the filters at that price, given the current exchange rate, but the shipping will almost double the cost :-(
Forget my last post. It seems list price for Kodak 5.5" safelight filters is ~$32 in the US, or ~£46 in the UK. Even including shipping it will cost me the same to buy 2 filters from B&H or one filter from Calumet in the UK!
B&H has a min shipping charge. Best not to order one small lite thing. Odds are you can find a few more small things and your shipping won't go up at all. Or at least not much.