Cobalt Blue Color Codes

Cobalt Blue is a dark, vivid azure blue with the hex code #0047AB, RGB values of 0, 71, 171 and an HSL value of hsl(215, 100%, 34%).

HEX	#0047AB
RGB	0, 71, 171
HSL	hsl(215, 100%, 34%)
HSV	215°, 100%, 67%
CMYK	100%, 58%, 0%, 33%
LAB	32.80, 22.52, -58.44
CIELCHuv	32.80, 82.05, 258.74°

Nearest Pantone: PMS 293 C ΔE 4.7 · approximate
Nearest CSS name: darkslateblue ΔE 16.9

Source Wikipedia, Cobalt blue (pigment PB28)

Cobalt Blue Color Hex Code

The Cobalt Blue color hex code is #0047AB. Those six digits are three pairs, 00 for red, 47 for green and AB for blue, which is the same triplet a browser reads from the CSS value below.

#0047AB

Cobalt Blue Color RGB Code

The Cobalt Blue RGB code is rgb(0, 71, 171). Blue carries the most light at 171 of 255, which is what puts this color where it sits on the wheel.

rgb(0, 71, 171)

Cobalt Blue Color HSV Code

The Cobalt Blue HSV code is 215°, 100%, 67%. Read it as a hue of 215 degrees, 100% saturation and 67% value, which is the form most color pickers use because moving one number changes one thing.

215°, 100%, 67%

Cobalt Blue Color CIELChuv Code

The Cobalt Blue CIELCHuv code is 32.80, 82.05, 258.74°. Unlike hex or RGB this one is perceptual: lightness 33 means dark to the eye rather than to the screen, and chroma 82 is how far it sits from grey.

32.80, 82.05, 258.74°

Tonal scale

What are Cobalt Blue Color Palettes?

A shade mixes toward black, a tint toward white, a tone toward grey. Every step keeps the hue and is copy-ready.

Shades, toward black

Tints, toward white

Tones, toward grey

Open in the shades & tints generator →

Palettes

What are Cobalt Blue Color Palette Codes?

Each of these is a hue rotation from #0047AB. They are generated, not curated, so they are exact.

Complementary

The opposite hue is #AB6400, a mid-tone, vivid orange. Complements carry the strongest contrast of any two-color scheme, so this pair suits a call to action better than a background. Both are saturated, so give the complement much less area than the base or the two will fight.

Analogous

Its two neighbours are #009DAB and #0F00AB. Because they overlap heavily in hue, nothing in the group competes, and the eye reads the whole set as a single color with variation.

Triadic

#AB0047 and #47AB00 complete an even 120 degree split. Three fully independent hues, so one has to lead: keep this base dominant and let the other two appear in small quantities.

Split-complementary

Instead of the direct complement, this takes the two hues either side of it: #AB0F00 and #9DAB00. Almost the same contrast, without the edge shimmer a true complementary pair produces at high saturation.

Tetradic

Two complementary pairs forming a rectangle: this base with #AB6400, and #AB009D with #00AB0F. The richest of the five and the hardest to balance, so treat this base as the lead and hold the other three well back.

See these on the color wheel →

Accessibility

Measured against white and against black, with a separate verdict for each element type. Small text, large text and UI components have different thresholds, so one pass or fail for the whole color would be wrong roughly a third of the time.

White background

8.44:1

8.44

contrast ratio on white background

Element	AA	AAA
Small text needs 4.5:1 / 7:1	Passes	Passes
Large text needs 3:1 / 4.5:1	Passes	Passes
UI component needs 3:1	Passes	n/a

Black background

2.49:1

2.49

contrast ratio on black background

Element	AA	AAA
Small text needs 4.5:1 / 7:1	Fails	Fails
Large text needs 3:1 / 4.5:1	Fails	Fails
UI component needs 3:1	Fails	n/a

Cobalt Blue clears WCAG AA against white at 8.44:1, so it is safe for body copy as well as headings. Text placed on it should be white, which gives 8.44:1. It is a highly saturated color, so it will dominate anything it sits beside. Give it space rather than surrounding it with other strong colors.

Check Cobalt Blue against another color →

Color vision

How Cobalt Blue looks with color blindness

Around 300 million people see color differently from the way it is specified. Each card shows the actual color beside how it appears, and how common that form of vision is.

Protanopia

About 1% of men

actual

#2E2E9A

Cobalt Blue shifts noticeably here. ΔE 14.9

No working red cones. Reds darken sharply and drift toward the same muddy olive as green.

Deuteranopia

About 1% of men

actual

#2A2596

Cobalt Blue shifts noticeably here. ΔE 19.4

No working green cones. With the milder deuteranomaly at nearer 6% of men, this is by far the most common form, and the one worth designing around.

Tritanopia

About 1 in 10,000

actual

#0A8B87

Cobalt Blue changes substantially here. ΔE 77.2

No working blue cones. Blues shift toward green and yellows toward pink. Rare, and unlike the others it is not sex-linked, so it affects men and women equally.

Achromatopsia

About 1 in 30,000

actual

#4D4D4D

Cobalt Blue changes substantially here. ΔE 62.6

No color vision at all. Also a fair proxy for how the color survives a greyscale print or a failing screen.

To a deuteranope, the most common form, Cobalt Blue reads as #2A2596. That is a shift of ΔE 19.4, so it is a different color to roughly one man in sixteen. Blues survive red-green deficiency well, which is why so much interface design leans on them. The form to watch here is tritanopia, though at roughly 1 in 10,000 it affects far fewer people. The widest shift is under tritanopia, at ΔE 77.2. The rule this leads to needs no simulator: never let color be the only thing carrying a message. Add a label, an icon, or a clear difference in lightness, and the problem disappears for everyone.

Simulate a whole palette →

Snippets

Using Cobalt Blue in code

:root {
  --cobalt-blue: #0047AB;
}

.example {
  color: var(--cobalt-blue);
}

// tailwind.config.js
theme: {
  extend: {
    colors: {
      'cobalt-blue': '#0047AB',
    },
  },
}

// SwiftUI takes 0–1 components, not 0–255.
let cobaltBlue = Color(
    red: 0.000,
    green: 0.278,
    blue: 0.671
)

<!-- res/values/colors.xml -->
<color name="cobalt_blue">#0047AB</color>

// Flutter wants ARGB: FF for full opacity, then the hex.
const cobaltBlue = Color(0xFF0047AB);

Meaning

What is the Meaning of Cobalt Blue Color?

Cobalt Blue reads as trust and institution. It is saturated enough to dominate anything it sits beside, and at 100% saturation with a perceptual lightness of 33 it behaves as a cool color, which is the practical reason it turns up where it does.

What are Other Names of Cobalt Blue Color?

The closest CSS keyword is DarkSlateBlue (#483D8B), though it is not a match: Delta-E 16.9 means the difference is visible side by side. For print the nearest Pantone is PMS 293 C at #0051BA. The name Cobalt Blue comes from the community color-name index rather than a standards body, so you will meet it under other names elsewhere.

How is Cobalt Blue Color Made?

On a screen Cobalt Blue is made by additive light: 0 red, 71 green and 171 blue out of 255, with blue leading and 0 as the floor. In print it is subtractive instead, mixed as 100%, 58%, 0%, 33%. Starting from the pure hue at 215 degrees, Cobalt Blue is close to the pure hue, with little white or black in it.