Pale crag martin to do so, it would cast doubts on their specific distinctness. There are several subspecies differing in plumage shade or size, although the differences are clinal, and races interbreed where their ranges meet. The pale crag martin of the nominate subspecies "P. o. obsoleta" is 12–13 cm (4.7–5.1 in) long with light brown upperparts, becoming paler on the lower back, and a short square tail that has small white patches near the tips of all but the central and outermost pairs of feathers. It has a pale grey throat, upper breast and underwing coverts, and the rest of the underparts
Buff (colour) The Bibby Line and the Fyffes Line are two of several firms to use the same "buff with a black top" scheme as White Star, but with a similar lack of certainty as to the exact shade used and how this differed from the famous White Star scheme. Buff (colour) Buff is the pale orange-brown colour of the undyed leather of several animals. As an RYB quaternary colour, it is the colour produced by an equal mix of the tertiary colours citron and russet. The first recorded use of the word "buff" to describe a colour was in "The London