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Sturdy Madras

#637be7
Notes

Sturdy Madras (#637BE7) is a true blue with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (229°, 73%, 65%) 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
#637be7
RGB
rgb(99, 123, 231)
HSL
hsl(229, 73%, 65%)
HWB
hwb(229 39% 9%)
OKLCH
oklch(61.7% 0.164 271.4)
P3
color(display-p3 0.4069 0.4796 0.8777)
HSV
hsv(229, 57%, 91%)
LAB
lab(54.64% 22.75 -57.57)
LCH
lch(54.64% 61.90 291.56)
CMYK
cmyk(57%, 47%, 0%, 9%)

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.

Madras
noun

Indian Coromandel Coast city (now Chennai) — once the British East India Company's premier indigo export depot, processing Bihar and Bengal Indigofera tinctoria before shipment to Europe. Madras color refers to a Madras-checked indigo-and-white cotton handloom: a saturated, slightly cool deep blue-violet with the matte finish of multi-bath fermentation indigo on hand-loomed Coromandel cotton.

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.

#637be7
Original
#4789eb
Protanopia
#347de5
Deuteranopia
#0093a6
Tritanopia
#7e7e7e
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).
AA Largeon White
3.81:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAon Black
5.52:1

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
##637BE7
Display P3
Display P3
color(display-p3 0.4069 0.4796 0.8777)
P3 has subtle headroomOKLCH chroma 0.164

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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