Alpine plants usually have blue leaves.

In fact red leaves indicate high levels of anthocyanins which are antioxidants which protect the leaves (or fruit) from various damage. There was an interesting catalyst show on this a few years back. blueberries are meant to be very good foryou as a result.

Carotenoids sort of carry away the extra sunlight energy in the form of unwanted electrons, from locations that could damage plant tissues and photosynthesis. Carotenoids are in carrots naturally, but how the sun is responsible for a root vegetable turning yellow/orange, is another story.

As for blue leaves in Alpine plants, the colour tends also to be a silver-grey. The lighter colour reflects some of the intense light. In Alpine situations the plant is much more exposed to the sun's harmful rays. Waxes on the leaf surface deflect ultra-violet rays etc., away from the leaf. Fine hairs also do the same as well as protecting against excessive water loss and also help insulate plants against frost/snow damage. The stomata tend to be fewer and more hidden to handle the harsh winds and temperatures. They are often found on the underside of the leaf. These factors will effect the colour of the leaves. Just look at heathland plants in any exposed coastal plant community and the leaf colour is pretty well the same as in the Alpine heathlands. Photosynthesis has to be minimised because of the exposed conditions. The leaves tend to be much much smaller as well.

It is all a case of the plant adapting to the environmental situation. Fascinating!!!