Outdoor camouflage fatigues work by breaking up the outline of the person wearing them by blending into the dappled greens of the jungle/forest/plains in which they are being worn.
Urban camouflage fatigues attempt to do the same thing, but with a collection of grey, blue or sandy tones. The problem
is that your average urban environment doesn't look like that.
Looking around your typical British (or other Western city) it wont be long before you come across the puerile daubings of variously unemployed glue-sniffing youves.
An army platoon garbed in the new Urban Grafitti Camouflage will have a collection of tags, petty insults and obscenities scribbled across them saying things like "Bazza wuz ere", "NUFC", "Mandy sucks cocks" or just "Banksy", in addition to crudely penned details of male and female genitalia.
Units so engarbed would appear almost invisible when holding out under a railway bridge or municipal bus depot.
Larger units such as tanks and mobile troop carriers might have more extravagant compositions in that big fat, hard to read blobby lettering.
Best of all, the costs for rebranding everything would be minimal and would require only leaving equipment overnight underneath a flyover somewhere, and fly pasting uniforms along brick walled railway sidings.