The spike antenna beneath the fuselage is for the I.F.F. and, as far as I know, was pale yellow.
On1950s RAF aircraft, these were normally a "solid" yellow, but in colour footage and stills of, for example, wartime Lancasters, the I.F.F. antenna looks to be a faded or pale yellow.
The boarding "stirrup" step would normally be either bare metal, or painted silver, as on the Hurricane, with the underside of the step itself in MSG.