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Unwavering Diǎnlán

#637cdc
Notes

Unwavering Diǎnlán (#637CDC) is a true blue 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 (228°, 63%, 63%) 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
#637cdc
RGB
rgb(99, 124, 220)
HSL
hsl(228, 63%, 63%)
HWB
hwb(228 39% 14%)
OKLCH
oklch(61.3% 0.148 270.5)
P3
color(display-p3 0.4078 0.4834 0.8370)
HSV
hsv(228, 55%, 86%)
LAB
lab(54.27% 18.59 -51.99)
LCH
lch(54.27% 55.21 289.68)
CMYK
cmyk(55%, 44%, 0%, 14%)

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.

Diǎnlán
noun

Chinese diǎnlán (深蓝) — deep blue, used for the saturated blue of Ming-dynasty cobalt-on-porcelain underglaze and the deep-blue silks of Han-period imperial robes. The color refers to a Ming-dynasty diǎnlán cobalt-on-porcelain plate: a saturated, slightly cool deep blue with the high gloss of fired porcelain glaze.

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.

#637cdc
Original
#5287e0
Protanopia
#437dda
Deuteranopia
#1e91a1
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
3.86:1
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
5.45:1

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
##637CDC
Display P3
Display P3
color(display-p3 0.4078 0.4834 0.8370)
P3 has subtle headroomOKLCH chroma 0.148

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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