A bright blue pigment or dye; elliptical a fabric dyed of this colour. azure of Almayne: ? Prussian blue.

A complex silicate containing sulphur, of bright blue colour, used as a pigment (see ultramarine, adj. n.). Also, the colour of this mineral.

A blue colouring matter, obtained from various lichens, esp. archil, Roccella tinctoria. Also figurative, as in litmus test.

A kind of pigment of a green, bluish green, or (more frequently) light blue colour, usually prepared by adding chalk or whiting to a solution of…

A blue pigment consisting of the scum collected from the vat in dyeing with woad or indigo.

The pigment which yields this colour, prepared from smalt; also a green pigment (green bice) made by adding yellow orpiment to smalt.

As a mass noun: a kind of glass, usually coloured deep blue by cobalt oxide, finely pulverized and used as a pigment or colouring matter in…

= smalt, n. 1a.

As a count noun: a powder or pigment made of such glass. Now rare.

= A. 3.

a blue pigment prepared from litmus.

Hence occasionally in plural.

ultramarine blue (or colour). A pigment or colouring matter of various shades of blue, originally obtained from the mineral lapis lazuli and named…

a blue pigment made from mercury, sulphur, and ammonium chloride.

Any of several deep blue pigments consisting chiefly of ferric ferrocyanide, Fe3+ 4[Fe2+(CN)6]3, used in painting and dyeing; the colour of such a…

An earthy form of the blue mineral Azurite (a hydrated basic copper carbonate); as a pigment, known as Lambert's Blue.

A blue powder (spec. smalt or azure) used to dye starch. Now historical.

a cobalt blue colour of any of various shades of light and dark; a pigment of this colour; a dye, paint, etc., made from this pigment.

= verditer, n. 1.

a brown pigment made from asphalt suspended in a drying oil; the colour of this.

= Prussian blue, n. adj., or the finest kind of it.

= litmus, n.

a light blue pigment, identified by some early authors as containing copper, but in later use typically a weakened form of Prussian blue (cf. mineral…

(a) artificial ultramarine; (b) colloquial a recreational drug consisting of amphetamine and a barbiturate (usually in plural).

= lapis lazuli, n.

a bright blue colour; cf. sense 9.

= Waterloo blue n. at sense 1. Obsolete.

The blue pigment, also called cobalt-blue n. prepared from this mineral, largely used in staining glass. Also the deep blue colour of this.

A bright blue pigment of considerable stability invented by Thénard, consisting essentially of cobalt aluminate; cobalt blue.

Any of various blue pigments containing iron, esp. Prussian blue (Prussian blue, n. 1).

transf. = litmus, n.

(the colour of) artificial ultramarine.

A blue aniline dye.

a variety of blue containing alumina.

the name of a permanent blue pigment, a compound of cobalt and Prussian blue.

an artist's colour prepared from cobalt, a brilliant light blue pigment.

In full Milori blue. A very pure variety of Prussian blue.

= Prussian blue, n. 1.

attributive in names of various things now or originally obtained, made, cultivated, etc. at or near… = phthalocyanine blue n. at phthalocyanine, n.…

In form gentianin. A plant pigment of the anthocyanin class, originally isolated from the blue flowers of a species of gentian (Gentiana acaulis).

A proprietary name for: a pigment belonging to either of two groups having exceptional fastness; (a) blue and green pigments that are derivatives of…

With following colour name: any of various cationic dyes derived mainly from copper phthalocyanine; esp. in Alcian Blue n. a water-soluble…