From Edwin A. Abbott's "Flatland", written in 1884.

The sight of a line of battle of twenty thousand Isosceles suddenly facing about, and exchanging the sombre black of their bases for the orange of the two sides including their acute angle; the militia of the Equilateral Triangles tricoloured in red, white, and blue; the mauve, ultra-marine, gamboge, and burnt umber of the Square artillerymen rapidly rotating near their vermillion guns; the dashing and flashing of the five-coloured and six-coloured Pentagons and Hexagons careering across the field in their offices of surgeons, geometricians and aides-de-camp -- all these may well have been sufficient to render credible the famous story how an illustrious Circle, overcome by the artistic beauty of the forces under his command, threw aside his marshal's baton and his royal crown, exclaiming that he henceforth exchanged them for the artist's pencil.

An online edition can be found at: http://www.alcyone.com/max/lit/flatland/8.html

Gamboge is new to me. Apparently it's a kind of yellow.
The AHD gives the new Latin gambogium or cambugium = Cambodia, as the source.http://www.bartleby.com/61/80/G0028000.html

Bingley

Bingley