Gray dye that looks red

I believe you have yourself there a Dye Remover, which is prenerf, removed from came back in 2006.

https://wiki.guildwars.com/wiki/Dye_Remover

They are somewhat useless now but can be collectable. The market right now appears to be around 5a-10a, however please wait for someone else to verify price that may have recently bought or sold one.