I'm not 100% certain about the radio altimeter, but it was probably fitted, with the "T" antenna on the underside of the main wings, outboard of the outer engine.
Colour scheme was RAF Dark Green (some sources state Light Green) and RAF Light Earth, both of these "Light" colours being just a touch lighter than the Dark Green / Dark Earth shades, with Medium Sea Grey under-surfaces.
The colour beneath the rear section of the canopy was the exterior camouflage colour, in this case, the Green. Code letters on this aircraft were yellow.
Hope this helps.