The bike looks to be finished in SCC No.2 Brown which would be correct for the majority of British manufactured vehicles in use in NW Europe during 1944. Although the new British Olive Drab colour was being introduced during early 1944, instructions were that existing paint stocks were to be used up first and unless your bike had been through a rebuild, it would not have received the OD colour (and if you go down this route then you should, strictly speaking be thinking about a census number from the 'rebuild' sequences).
Regrettably, the display of Formation Signs on motorcycles was discontinued in accordance with Army Council instructions of October 1943. The only markings displayed thereafter were the Arm of Service insignia, usually on both sides of the fuel tank.
The Arm of Service marking for Divisional Signals in an infantry division at this point was a red '40' over the white / blue signals colours.
This scheme does not unfortunately give any indication of the division involved and perhaps therefore it is not uncommon to see restored bikes with the divisional Formation sign applied to the right hand side of the fuel tank although this is correctly a layout which was discontinued prior to June 1944.