colors
Back to gallery

Noble Sinii

#3663b1
Notes

Noble Sinii (#3663B1) is a true azure with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (218°, 53%, 45%) 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
#3663b1
RGB
rgb(54, 99, 177)
HSL
hsl(218, 53%, 45%)
HWB
hwb(218 21% 31%)
OKLCH
oklch(50.8% 0.134 260.6)
P3
color(display-p3 0.2540 0.3839 0.6726)
HSV
hsv(218, 69%, 69%)
LAB
lab(42.58% 11.02 -46.11)
LCH
lch(42.58% 47.41 283.44)
CMYK
cmyk(69%, 44%, 0%, 31%)

Etymology

Noble
adjective

Latin nōbilis, well-known / illustrious — sharing root with gnōscere (to know). As a color modifier, noble implies a saturated-and-dignified-and-aristocratic quality, the deep-rich color of pre-modern European noble-class hereditary-aristocratic livery-and-armorial bearings. Sits at the bold-and-aristocratic end of the grid, parallel to aristocratic and highborn in usage.

Sinii
noun

The Russian word for deep blue — distinct from goluboy (light/sky blue) in Russian color vocabulary, which (uniquely among major languages) names two separate basic blue categories. The color refers to a sinii-painted Russian Orthodox church dome: a saturated, slightly cool very deep blue with the matte finish of distemper-and-pigment paint.

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.

#3663b1
Original
#3d6bb4
Protanopia
#275faf
Deuteranopia
#007581
Tritanopia
#5f5f5f
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
5.87:1
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
3.58:1

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
##3663B1
Display P3
Display P3
color(display-p3 0.2540 0.3839 0.6726)
P3 has subtle headroomOKLCH chroma 0.134

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.

Related Colors

Canvas