cobalt blue

American  

noun

1. a deep blue to a strong greenish-blue color.

2. any of a number of pigments containing an oxide of cobalt.

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cobalt blue British  

noun

1. Also called: Thénard's blue.  any greenish-blue pigment containing cobalt aluminate, usually made by heating cobaltous sulphate, aluminium oxide, and phosphoric acid together

2. 1. a deep blue to greenish-blue colour

   2. ( as adjective )

      a cobalt-blue car

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Etymology

Origin of cobalt blue

First recorded in 1825–35

Compare meaning

How does cobalt-blue compare to similar and commonly confused words? Explore the most common comparisons:

• cobalt blue vs. royal blue

Example Sentences

See Examples For:

cobalt blue

The blue-tinted lenses seemed to resonate perfectly with the cobalt blue background of the Davos stage, creating a striking effect.

From The Wall Street Journal ● Jan. 22, 2026

At New York Fashion week, coloured mascara was all the rage and the cobalt blue mascara was a particular stand out at LaQuan Smith's catwalk.

From BBC ● Sep. 11, 2024

It turns out that sky blue is close enough to cobalt blue for these justices.

From Slate ● Jul. 22, 2024

Another of them, rendered almost invisibly in shellac on deep cobalt blue moiré, circles around to give the exhibition its trenchant title: “Now then, as I was about to say …”

From Los Angeles Times ● Apr. 7, 2024

Wiping cookie crumbs from his mustache, he turned into the main road, and there, outlined in cobalt blue, stood Guitar.

From "Song of Solomon" by Toni Morrison