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Sturdy Oxford

#173f99
Notes

Sturdy Oxford (#173F99) is a true 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 (222°, 74%, 35%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. 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
#173f99
RGB
rgb(23, 63, 153)
HSL
hsl(222, 74%, 35%)
HWB
hwb(222 9% 40%)
OKLCH
oklch(40.0% 0.154 263.1)
P3
color(display-p3 0.1327 0.2436 0.5783)
HSV
hsv(222, 85%, 60%)
LAB
lab(29.50% 21.87 -52.95)
LCH
lch(29.50% 57.29 292.45)
CMYK
cmyk(85%, 59%, 0%, 40%)

Etymology

Sturdy
adjective

Old French estourdi, stunned, reckless — drifted in English to mean robust, well-built. Used as a color modifier since the seventeenth century for hues that read as durable and unfussy — the working browns of saddle leather, the working greens of pasture wool. Sits in the bold-and-warm corner alongside robust and solid.

Oxford
noun

The athletic blue of the University of Oxford — adopted alongside Cambridge's lighter blue in the 1820s, when the two universities first began racing crews against each other on the Thames. The color refers to an Oxford-blue rowing jersey: a saturated, slightly muted deep blue with the matte finish of melton wool. Deeper than navy, cooler than royal, with the rivalrous heraldic weight of a color paired with its institutional opposite.

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.

#173f99
Original
#004c9c
Protanopia
#004097
Deuteranopia
#005665
Tritanopia
#3d3d3d
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
9.51:1
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
2.21:1

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
##173F99
Display P3
Display P3
color(display-p3 0.1327 0.2436 0.5783)
P3 has subtle headroomOKLCH chroma 0.154

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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