When on operations, especially ashore, it is not uncommon for Royal Navy personnel to wear MTP combat uniforms. Those wearing these uniforms obviously wish to make it clear that they are members of the RN and not the army. Most RN combat uniforms will have ‘Royal Navy’ shoulder titles sewn to the top of the sleeves, however the wearing of white ensign patches on the sleeve is also popular. Obviously a large white, red and blue patch would not be appropriate on a camouflage uniform so subdued patches are used instead:
Here then are two variants, one which uses green in place of the red and another that uses brown, the white is replaced with a sand colour in both:
As combat uniforms need to be washed regularly, these patches are designed to use velcro to allow them to be taken on and off easily. Each of the patches has the hook side of the velcro attached to the back, and a suitably sized piece of loop fabric is provided that can be sewn to the sleeve:
As well as being helpful for washing, having the insignia easily detached can help with operational security when it is necessary to disguise the units of particular personnel- it is very easy to just pull these ensigns off and put them in a pocket.
I am unsure if these patches are actually issued by the RN, or are privately purchased by individuals wishing to make it clear their service.
Tales from the Supply Depot 
Another great post.
To answer your self query, these patches were privately bought. The RN did issue TRFs for CS95 but these were miniature badges of the Royal Navy logo and only worn by RN personnel, this blue badge would have been worn on the right sleeve with a “Royal Navy” tape above the breast pocket. These were soon replaced by the “mudguard style flashes. Though there are rules about what flashes are worn on PCSCU not many people adhered to them and all sort of badges and insignia were created to make us blue jackets stand out when wearing green.
There is a new official subdued ensign badge coming out very soon, for wear on all camouflage uniforms by Royal Navy and Royal Marines, this badge will be a black ensign pattern on a green background and will show that the wearer is part of the naval service whether marine or sailor.
Thanks, its been a while since I left the mob- must confess my MTP wasn’t exactly regulation either- Had a large ‘Royal Navy’ name tape worn over one pocket that I probably shouldn’t have!
With regard to modern camouflage uniforms, there is a conflict between the camouflage aspect to make the wearer less conspicuous and the need for positive identification. You’ve probably heard of how the US Army stopped using camouflage uniforms in Europe after D-day to prevent confusion with Germans wearing camouflage uniforms. In both cases, however, camouflage uniforms were not widely issued.
There’s probably an over emphasis on the little details of camouflage anyway. Although plain olive green uniforms were on issue when I was in the service in the 1960s, as they were in the British armed forces, they were still decorated with colored unit shoulder patches, “U.S.ARMY” tapes with gold letters and white sewn-on name tapes, along with the specialty badges, like parachute qualification badges, that seem to be worn in all armies, all in color. However, subdued name tapes and badges were in use by the end of the 60s. National flags came later, apparently in color.