A rainbow is a multi-colored arc found in the sky in rainy or misty weather. As depicted in heraldry, it’s an arc fesswise, embowed to chief, the ends terminating in clouds. The default heraldic rainbow has four bands; when blazoned “proper”, these bands are Or, gules, vert, and argent, with argent clouds [Parker 488]. On a light field, the bands’ order is changed: azure, vert, Or, and gules, with the tincture of the clouds to be specified. The rainbow is a period charge: a rainbow throughout proper is found in the arms of von Mosen, 1605 [Siebmacher 159].
The “natural rainbow proper”, a Society invention, has white clouds, and seven colored bands, as found in nature: red, orange, yellow, green, blue, indigo, and violet. As it’s the rainbow, not the clouds, that must be recognized, a natural rainbow proper may not be used on a color field. Its use is considered a step from period practice. See also heavenly bodies.
The Baron of Sundragon bears: Argent, a rainbow gules, argent, azure, Or and purpure, clouded within a laurel wreath azure.
Adriana of Hawkwood bears: Ermine, a rainbow proper clouded azure, a bordure sable.
Gabrielle Cartier bears: Or, a natural rainbow proper clouded sable, a chief indented pean.