Lee Enfield No4 Mk1 Sling Question

[Strangely Brown]

Post war khaki slings in service with RTR, RE, RA and certain Infantry regiments were blackened with boot polish. This was by no means universal and sometimes only done in training and depot units.
After finishing boys service and getting posted to my first regiment the mix of slings was unbelievable, khaki, green, black, and I think we even had some of the new nylon? dark green slings circa 1970.