Off the top of my head, I can't think of any
Also, I don't recall reading about Langsdale having a foot regiment, but that's not to say he didn't, as I've got the most terrible memory.
You could to try and find all the manufacturers of ECW colours and standards and trawl through their catalogues.
I do have the Partizan Press ECW Colours books somewhere, but haven't seen them for years, so I'm afraid I can't give you a definitive answer. They are very good references though and if you don't have them, I'd recommend getting them.
Maybe you could try e-mailing Dave Ryan at Caliver Books, as he would probably either be able to tell you or point you to a reliable source.