colors
Back to gallery

Cold Crude

#040d21
Notes

Cold Crude (#040D21) 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 (221°, 78%, 7%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#040d21
RGB
rgb(4, 13, 33)
HSL
hsl(221, 78%, 7%)
HWB
hwb(221 2% 87%)
OKLCH
oklch(16.3% 0.045 261.7)
P3
color(display-p3 0.0221 0.0499 0.1240)
HSV
hsv(221, 88%, 13%)
LAB
lab(3.82% 2.70 -13.72)
LCH
lch(3.82% 13.98 281.14)
CMYK
cmyk(88%, 61%, 0%, 87%)

Etymology

Cold
adjective

Old English ceald, of low temperature — used as a color modifier since the medieval period for hues with a slight blue or blue-green shift, even within otherwise neutral grays. Cold gray, cold white: the optical impression of a low-temperature reflective surface. Sits in the neutral-and-cool corner alongside icy.

Crude
noun

Latin crūdus, raw — adopted into English as the technical term for raw petroleum (crude oil), the deep-iridescent-black multi-component hydrocarbon mixture extracted from Spindletop-style oil-fields. Crude color refers to a freshly extracted West-Texas-Intermediate crude oil sample in a clear-glass cup: a saturated, slightly cool deep black with the iridescent satin finish of multi-component hydrocarbon mixture against the clear-glass background.

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.

#040d21
Original
#040f22
Protanopia
#010c21
Deuteranopia
#001215
Tritanopia
#0d0d0d
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
19.36:1
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
1.08:1

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
##040D21
Display P3
Display P3
color(display-p3 0.0221 0.0499 0.1240)
Inside sRGBOKLCH chroma 0.045

This color sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.

Related Colors

Canvas