It was part of the ex planning process for the Tornado GR Force. Managed to get disruptive pattern white/grey and white/green for Ex ARCTIC EXPRESS in the 90s but that was when disruptive pattern worked well at low level. As BV says, now we are at medium level (to stay - discuss?) Medium Sea Grey was the default setting of the Camouflage Working Group that was about as operator friendly as the good old Ordnance Board ;-)