In the western SBA there is a mix of desert combats and Stone Drill. The majority seem to prefer the long trousers of the combats and boots even when working in an office in HQ.
This fashion for wearing free combats seems to have followed the same pattern as in UK but unlike UK has not been stopped. Of course in winter months the combats would be worn instead of blues.
The women, OTOH, seem to prefer the bell tents and sandals rather than combats if they are in office jobs.
The RAF rule to wear blue 'barrack dress' is probably two edged - one is a desparate attempt to retain a separate identity and the other because issue blues are cheaper than issue combats.
The Army, with no such identity crisis, seems happier with its office wallahs wearing a uniform with distinguishing patches, cockades, belts and what have you.