(n.) The quality of being blue; a blue color.

Caelus achievement air alerion animal charge annulet argent armorial bearings armory arms azure-blue azure-colored azurean azured azureness azureous bandeau bar bar sinister baton bearings bend bend sinister beryl-blue berylline billet blazon blazonry blue blue sky blueness bluish bluishness bordure broad arrow cadency mark caelum canopy canopy of heaven canton cerulean ceruleous cerulescent chaplet charge chevron chief coat of arms cockatrice cope coronet crescent crest cross cross moline crown cyanean cyanosis dark-blue deep-blue device difference differencing eagle empyrean ermine ermines erminites erminois escutcheon ether falcon fess fess point field file firmament flanch fleur-de-lis fret fur fusil garland griffin gules gyron hatchment heaven heavens helmet heraldic device honor point hyaline impalement impaling inescutcheon label lift lifts light-blue lightish-blue lion livid lividity lividness lozenge mantling marshaling martlet mascle metal motto mullet nombril point octofoil or ordinary orle pale paly pavonian pavonine peacock-blue pean pheon purpure quarter quartering rose sable saltire sapphire sapphirine scutcheon shield sky sky-blue sky-colored sky-dyed spread eagle starry heaven subordinary tenne the blue the blue serene tincture torse tressure turquoise unicorn vair vault vault of heaven vert welkin wreath yale