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Plainspoken Cobaltite

#04588b
Notes

Plainspoken Cobaltite (#04588B) is a deep azure with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (203°, 94%, 28%) places it in the highly saturated band at a dark lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. For a confident two-color system, pair it with its complementary orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#04588b
RGB
rgb(4, 88, 139)
HSL
hsl(203, 94%, 28%)
HWB
hwb(203 2% 45%)
OKLCH
oklch(44.4% 0.109 244.5)
P3
color(display-p3 0.1443 0.3396 0.5293)
HSV
hsv(203, 97%, 55%)
LAB
lab(35.73% -2.05 -34.41)
LCH
lch(35.73% 34.47 266.58)
CMYK
cmyk(97%, 37%, 0%, 45%)

Etymology

Plainspoken
adjective

English compound plain + spoken — past-participle of speak. As a color modifier, plainspoken implies a clear-and-direct-and-straightforward quality where the hue carries the visual register of unembellished-honest declaration. Sits at the crisp-and-honest end of the grid, parallel to candid and direct in usage.

Cobaltite
noun

A cobalt-arsenic-sulfide mineral — the principal historical source of cobalt for ceramic and pigment use. Mined principally in Cobalt, Ontario (the source of the modern cobalt-mining industry's name). The color refers to a polished cobaltite crystal: a soft, slightly cool deep blue-silver with the metallic finish of crystallized cobalt mineral.

Closest matches

The nearest named color in three reference sources, ranked by perceptual distance (ΔE76 in CIELAB). ΔE < 1 is imperceptible to most viewers; ΔE > 10 is clearly different. When two sources point to the same hex they’re merged into one tile; click any to open that color’s page.

Variations

Click any swatch to explore

Harmonies

Accessibility

Color-vision simulation

How this color appears to viewers with the four major color-vision-deficiency types. Computed via the Machado (2009) physiologically-based model. If a tile matches the original, the color reads the same to that viewer.

#04588b
Original
#3f5a8d
Protanopia
#2c4f8a
Deuteranopia
#00656b
Tritanopia
#4a4a4a
Achromatopsia
WCAG contrast

The color used as foreground text against pure white and pure black, with the contrast ratio and WCAG 2.1 grade. Aim for AA (4.5:1) for body text and AA Large (3:1) for 18 pt+ headlines; AAA (7:1) is the gold standard for long-form reading surfaces.

The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAAon White
7.57:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon Black
2.77:1

Wide gamut

Display P3 representation

The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.

sRGB hex
sRGB hex
##04588B
Display P3
Display P3
color(display-p3 0.1443 0.3396 0.5293)
P3 has subtle headroomOKLCH chroma 0.109

Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.

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