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Grounded Tsuyukusa

#3647a5
Notes

Grounded Tsuyukusa (#3647A5) is a true blue 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 (231°, 51%, 43%) 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
#3647a5
RGB
rgb(54, 71, 165)
HSL
hsl(231, 51%, 43%)
HWB
hwb(231 21% 35%)
OKLCH
oklch(44.1% 0.152 271.1)
P3
color(display-p3 0.2253 0.2765 0.6244)
HSV
hsv(231, 67%, 65%)
LAB
lab(34.00% 24.90 -52.83)
LCH
lch(34.00% 58.41 295.23)
CMYK
cmyk(67%, 57%, 0%, 35%)

Etymology

Grounded
adjective

Old English grund, bottom / foundation — past-participle of ground. As a color modifier, grounded implies a saturated-and-foundational quality where the hue anchors the surrounding palette through its weighty presence. Sits at the bold-and-balanced end of the grid, parallel to centered and anchored.

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.

#3647a5
Original
#0055a8
Protanopia
#004ba3
Deuteranopia
#005e6f
Tritanopia
#4a4a4a
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).
AAAon White
8.07:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon Black
2.60:1

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
##3647A5
Display P3
Display P3
color(display-p3 0.2253 0.2765 0.6244)
P3 has subtle headroomOKLCH chroma 0.152

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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