Hi Steve, good to have met you yesterday. White razor foam, tried all the usual suspects as I expect you have but no-one lists white for some reason.
What is it you need if for, as
www.deercreek.co.uk list some "translucent" colours. I've had some samples & they are (arguably) just translucent. I suppose you could use some thin white vinyl sheeting over it. I mean there's usually a several ways around these "challenges". Tee shirt paint perhaps.
I'll p.m. you my contact numbers so we can chat about it, but this afternoon & Monday a.m. are out as I'll be dealing with various hospital "things".
Cheers