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Unwavering Tsuyukusa

#1858cd
Notes

Unwavering Tsuyukusa (#1858CD) 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 (219°, 79%, 45%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. 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
#1858cd
RGB
rgb(24, 88, 205)
HSL
hsl(219, 79%, 45%)
HWB
hwb(219 9% 20%)
OKLCH
oklch(49.6% 0.192 261.4)
HSV
hsv(219, 88%, 80%)
LAB
lab(40.54% 25.78 -65.75)
LCH
lch(40.54% 70.63 291.41)
CMYK
cmyk(88%, 57%, 0%, 20%)

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.

Tsuyukusa
noun

Commelina communis, the Japanese dayflower — a wildflower whose deep blue flowers were used in the seventeenth century as a textile dye and aobana paper for yuzen dyeing patterns. Tsuyukusa-iro (露草色) refers to the saturated blue of fresh dayflower. The color refers to a fresh dayflower bloom: a saturated, slightly cool deep blue with the satin finish of three-petaled flower.

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.

#1858cd
Original
#0068d1
Protanopia
#0058cb
Deuteranopia
#00768a
Tritanopia
#535353
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).
AAon White
6.33:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.32:1

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