|Steingrau-Oliv Feldanzug with Parka|
About a hundred years ago, grey was found to be a shade (not exactly a "colour") that doesn't attract attention and is thus viable as a basic camouflage colour in pretty much every environment.
I'd argue that even the Bundeswehr's Cold War-era standard individual camouflage was a mixture of grey and green (officially "Steingrau-Oliv", also commonly called "Moleskin" or "olivgrün").
I've noticed that -at least in the anglophone world - the time-proven grey appears to be out of fashion. The Multicam pattern fashion swept away some stupid camouflage patterns, and the colour "Coyote" or "Coyote brown" (a shade of brown) appears to be the colour in fashion for applications without camo pattern. It reminds me of the famous khaki colour which played a similar role as grey outside of Europe
The reasoning is simply that some equipment does not need a camouflage pattern or should be usable with different camouflage patterns. This applies to pouches or very small items, for example.
|Example: Multicam + Coyote|
The No.1 concern is of course the contrast to the camouflage pattern; a stark contrast between patterned clothes and light brown equipment might make the soldier very discernible even in advantageous terrain. That's in part a general problem with the shape of the equipment and in part a general problem with homogeneous colouring.
Adding regularly shaped monochrome components to a well-designed camo pattern is not the way to go in regard to minimum detectability, after all.
The namesake, the Coyote, doesn't have a single large monochrome patch on his pelt. It's rather using different shades of colour for his evolution*-optimised pelt.
|A coyote, photograph by G Dan Hutcheson|
A force that's really serious about optimising its individual service members' camouflage cannot rely on a combination of a good camo pattern and a monochrome accessories colour.
The way to go is in my opinion - and this should not surprise since I advocated this for years- to primarily rely on shapes for camouflage, not on colouring (see here as well).
This in turn means that not only the attention on more or less fashionable camouflage patterns is ill-advised; it's not very important what colour or pattern you use for accessories either.
The colour "Coyote" has the advantage of being more pleasant to the human eye than grey, and is thus likely a good choice. It's furthermore OK to use it for accessories together with different camo patterns - as long as we're not talking about the normal Flecktarn or similar rather dark camo patterns.
The contrast between Flecktarn and Coyote would be too great, too discernible. I'm not very much in love with the darkness of normal Flecktarn anyway, but it's undisputedly great when you're hiding in the dark shade of a tree or other large object (and it's usually hard to hide anywhere else anyway).
*: I guess that counts as evidence for Anti-Americanism for my troll(s). ;)