The PR Spits were indeed a much paler pink than has often been shown, particularly on some scale models. The colour was developed, after the greenish hued 'cammotint', to be effective, as already described, in certain lighting conditions against cloud or haze background, at medium level, as opposed to the PRU Blue used for high altitude operations.
This was made more effective by the reflection of UV light off the clouds, which gave a feint pinkish tinge to the light, thus blending the aircraft into the background. This is similar to the pinkish haze often witnessed just above brightly lit, or side lit snow. During the Gulf War, as Adler quite rightly stated, a similar, although darker hued pink finish was applied to RAF Jaguar, Buccanneer and Torndao GR1 aircraft, not only as a camouflage to blend with the desert landscape, but also to blend in with the heat haze or dust-tinged light at low level.
The original S.A.S. Series II Land Rover 'Pinkies' were painted in a pink-tinged, mid stone finish, which, after prolonged exposure to strong sunlight and wind, faded to an even 'pinker' tinge. Subsequent SF vehicles for desert ops have employed a colour scheme not dissimilar to that used on some WW2 British vehicles in the Western Desert, utilising sand, stone,browns, blues and grey colours, plus, in most cases, an infra-red absorbing coating, to provide a similar rate of IR refllectance as would be expected to be recorded from natural materials.