RECENTLY I have noticed, with some dismay and increasing concern, that large sections of slopes, primarily those adjoining roads, are being engulfed by a spreading grey fungus. My mate, a respected Welsh rock doctor (geotechnical engineer) tells me this is 'shotcrete'. I can certainly see the aptness of this name considering the gay abandon with which it seems to be sprayed about without too much concern for any intervening vegetation. Apparently this grey muck stops the slopes from falling down in the rain, performing a similar function to the nicer green vegetation it replaces. What I want to know is why does it have to be such a harsh grey finish. My mate says he can do wonderful things with shotcrete, including making it all the colours of the rainbow - he has some particularly good earthy greens and browns.