Bleu celeste ("sky blue") is a rarely occurring tincture in heraldry (not being one of the seven main colours or metals or the three "staynard colours"). This tincture is sometimes also called ciel or simply celeste. It is depicted in a lighter shade than the range of shades of the more traditional tincture azure, which is the standard blue used in heraldry.
Initially considered to be European rather than English or Scottish, after the First World War it became more prevalent in England in badges relating to the Royal Air Force, or the arms of those with some RAF connection. While in the post-WWI period bleu-celeste is depicted as a darker shade, in prior times it was depicted as very light, and has even been treated as a metal, as azure charges have been placed on a bleu celeste field, and vice versa.
Bleu celeste can be seen in the arms of Argentina and Peru and also in the arms of former Canadian Governor General Ray Hnatyshyn. In the arms of the University of Natal Athletic Union the azure is defined as "sky blue".
In addition to bleu celeste, there is also an apparently unique example in British heraldry of the use of "light blue" in the Municipal Borough of Barnes, through which the Oxford versus Cambridge boat race passes on the Thames. The arms show the respective blades of the teams' oars, and may be blazoned thus:
- Azure, on a saltire or between four ostrich feathers argent, two oars in saltire proper, the blade of that to the dexter dark blue and that to the sinister light blue. (Blue with a yellow saltire "x" between four white feathers, the two paddles crossed and lying along and atop the saltire)
When in 1965 that borough merged with its neighbours to form the Borough of Richmond upon Thames, the coloured oars were transferred to the supporters in the arms of the new borough.
- Scott-Giles, C. W. (1958). Boutell's Heraldry (rev. ed.). London & New York: Frederick Warne & Co.