It is probably mostly to do with tradition. The natural local building material is stone - if it is not ON the surface, bedrock is pretty close the surface almost everywhere on Skye. You don't see any brick-built buildings here. There's no clay to make bricks, and anyway, brick tends to be porous, so would not be ideal for use in the West Highlands weather conditions. So, the earliest dwellings were simply stone-coloured. When lime mortar became available, the stone would be daubed with this, which when dry has a pale grey colour. A limewash might then be applied - making the final finish white(ish) in colour.
Scroll-on to the 20th century, and masonry paint is invented - available in a multitude of colours. A few old buildings in the most famous photo-spots, like Portee harbour, get painted blue, pink and yellow - but everywhere else - we tend to stick to white.
Modern buildings continue the white trend - though almost none are built of stone these days. Since the 1970s, houses here are constructed using a pre-fabricated, pre-insulated timber frame which is then clad with more insulation and covered with concrete blocks, making a strong outer layer. A cement render is then applied to the blocks, to provide a fully waterproof skin. Invariably, the render is decorated with a few coats of white masonry paint.
Maybe one day it will become fashionable to paint houses here in other colours - but for now, white looks good to me...
|Houses of all ages in Glendale - and all painted white!|