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Unwavering Tetsukon

#307cd7
Notes

Unwavering Tetsukon (#307CD7) is a true azure with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (213°, 68%, 52%) 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
#307cd7
RGB
rgb(48, 124, 215)
HSL
hsl(213, 68%, 52%)
HWB
hwb(213 19% 16%)
OKLCH
oklch(58.6% 0.158 255.2)
HSV
hsv(213, 78%, 84%)
LAB
lab(51.78% 8.62 -53.28)
LCH
lch(51.78% 53.98 279.19)
CMYK
cmyk(78%, 42%, 0%, 16%)

Etymology

Unwavering
adjective

Old English un- (negation) plus wafrian (to flicker). As a color modifier, unwavering implies a saturated-and-constant quality where the hue maintains its full strength without flicker or shift. Sits at the bold-and-firm end of the grid, parallel to steadfast and firm 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.

#307cd7
Original
#4f84db
Protanopia
#3074d5
Deuteranopia
#00929f
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
4.21:1
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
4.99:1

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