I got the original green RBL "Unknown Warrior" badge and a red fridge magnet three year ago , today on eBay I spotted (and snapped up !) a red version of the badge .
As the actual nameplate they unveiled was green I wonder if the red design was an alternate option , when they had to remove the RBL logo the new nameplate had the red background.
A clip showing the RBL unveiling the "original" nameplate :
https://www.youtube.com/watch?v=vDZz45FRtdk
.