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Refreshing Diadem

#6366b8
Notes

Refreshing Diadem (#6366B8) 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 (238°, 37%, 55%) 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 yellow. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#6366b8
RGB
rgb(99, 102, 184)
HSL
hsl(238, 37%, 55%)
HWB
hwb(238 39% 28%)
OKLCH
oklch(54.7% 0.126 279.8)
P3
color(display-p3 0.3904 0.3996 0.7001)
HSV
hsv(238, 46%, 72%)
LAB
lab(46.47% 20.76 -43.85)
LCH
lch(46.47% 48.52 295.33)
CMYK
cmyk(46%, 45%, 0%, 28%)

Etymology

Refreshing
adjective

Old French refreschir, to make fresh again — present-participle of refresh. As a color modifier, refreshing implies a clear-and-cool-and-revitalizing quality, the crisp color of Cornish-coast and Hebridean-island fresh-sea-air-and-cool-water revitalization. Sits at the crisp-and-cool end of the grid, parallel to fresh and bracing in usage.

Diadem
noun

Greek diádēma, bound-around — the imperial-and-royal headband adopted into Western regalia from the Persian Achaemenid royal kidaris. The British Imperial State Crown's diadem features the deep-blue Stuart Sapphire. Diadem color refers to the Stuart Sapphire face of the Imperial State Crown's diadem: a saturated, slightly cool deep blue-violet with the glassy finish of polished Ceylon sapphire under display lighting.

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.

#6366b8
Original
#4671bb
Protanopia
#406bb6
Deuteranopia
#467786
Tritanopia
#6b6b6b
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
5.09:1
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
4.12:1

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
##6366B8
Display P3
Display P3
color(display-p3 0.3904 0.3996 0.7001)
P3 has subtle headroomOKLCH chroma 0.126

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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