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Bulky Tetsukon

#337cce
Notes

Bulky Tetsukon (#337CCE) is a true azure with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (212°, 61%, 50%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#337cce
RGB
rgb(51, 124, 206)
HSL
hsl(212, 61%, 50%)
HWB
hwb(212 20% 19%)
OKLCH
oklch(58.2% 0.145 253.7)
P3
color(display-p3 0.2784 0.4800 0.7840)
HSV
hsv(212, 75%, 81%)
LAB
lab(51.35% 5.64 -48.86)
LCH
lch(51.35% 49.18 276.59)
CMYK
cmyk(75%, 40%, 0%, 19%)

Etymology

Bulky
adjective

Old Norse búlki, cargo / mass — adjectival suffix -y. As a color modifier, bulky implies a saturated-and-massive-and-occupying quality where the hue takes up visual space with broad-and-heavy presence. Sits at the bold-and-weighty end of the grid, parallel to hefty and substantial in usage.

Tetsukon
noun

Japanese tetsukon (鉄紺) — iron navy, the saturated dark blue of Meiji-period samurai ceremonial robes and the kasuri (ikat) textiles of pre-modern rural Japan. The color refers to a tetsukon-dyed kasuri cotton: a deep, slightly cool dark blue with the matte finish of multi-bath dyed 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.

#337cce
Original
#5582d1
Protanopia
#3c74cc
Deuteranopia
#008f9b
Tritanopia
#727272
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
4.27:1
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
4.92:1

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
##337CCE
Display P3
Display P3
color(display-p3 0.2784 0.4800 0.7840)
P3 has subtle headroomOKLCH chroma 0.145

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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