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Wellbred Slate

#303b9c
Notes

Wellbred Slate (#303B9C) is a true blue with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (234°, 53%, 40%) 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
#303b9c
RGB
rgb(48, 59, 156)
HSL
hsl(234, 53%, 40%)
HWB
hwb(234 19% 39%)
OKLCH
oklch(40.6% 0.157 272.4)
P3
color(display-p3 0.1967 0.2301 0.5895)
HSV
hsv(234, 69%, 61%)
LAB
lab(29.80% 28.62 -54.24)
LCH
lch(29.80% 61.33 297.81)
CMYK
cmyk(69%, 62%, 0%, 39%)

Etymology

Wellbred
adjective

Old English wel-brēd, well-bred — past-participle of breed, sharing root with brood (offspring). As a color modifier, wellbred implies a saturated-and-elegant-and-formal quality, the deep-rich color of Edwardian-period finishing-school-and-debutante-Court English-aristocratic livery. Sits at the bold-and-elegant end of the grid, parallel to highborn and patrician.

Slate
noun

A fine-grained metamorphic rock formed from compressed shale — fissile, durable, and the standard roofing material for Welsh and Vermont houses since the nineteenth century. The color refers to a freshly split piece of Welsh slate: a soft, slightly muted gray-blue with the matte finish of a layered mineral cleavage. Cooler than steel, lighter than navy, with the architectural weight of a roof material that lasts a hundred years.

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.

#303b9c
Original
#004b9f
Protanopia
#00419a
Deuteranopia
#005365
Tritanopia
#404040
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
9.41:1
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
2.23:1

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
##303B9C
Display P3
Display P3
color(display-p3 0.1967 0.2301 0.5895)
P3 has subtle headroomOKLCH chroma 0.157

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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