Racism in the barracks

racism exists in all armies,
but there are many black soldiers in US army
but in every picture of British soldiers from Afghanistan or Iraq, i never see a black face,
is that due to not many black/brown people applying into the army?
or that racism in army puts black/brown off applying?
minorities arnt well represented in the UK police force either, that i can attest that it is due to full on racism,
i'm not sure whether that is the case in USA or whether hollywood paints a beautiful picture of always pairing a white cop with a minority cop
as for me i am never gonna join the army, although becoming a sniper would be cool