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Commanding Tanzanite

#3737aa
Notes

Commanding Tanzanite (#3737AA) 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 (240°, 51%, 44%) 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
#3737aa
RGB
rgb(55, 55, 170)
HSL
hsl(240, 51%, 44%)
HWB
hwb(240 22% 33%)
OKLCH
oklch(41.6% 0.178 275.4)
P3
color(display-p3 0.2157 0.2157 0.6417)
HSV
hsv(240, 68%, 67%)
LAB
lab(30.51% 37.09 -61.52)
LCH
lch(30.51% 71.83 301.09)
CMYK
cmyk(68%, 68%, 0%, 33%)

Etymology

Commanding
adjective

Latin commendāre, to entrust / order — present-participle of command. As a color modifier, commanding implies a saturated-and-authoritative quality where the hue claims visual leadership of its surrounding palette. Sits at the bold-and-authoritative end of the grid, parallel to authoritative and imperial in usage.

Tanzanite
noun

A blue-violet variety of zoisite — discovered in 1967 in a single small area of northern Tanzania near Mount Kilimanjaro and marketed by Tiffany & Co. shortly after. The color refers to a faceted tanzanite cut to maximize its strong pleochroism: a saturated, slightly violet-shifted deep blue-purple with the gem's signature internal life. Cooler than amethyst, warmer than iolite, with the gem-trade specificity of a stone that occurs in exactly one place on Earth.

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.

#3737aa
Original
#004dae
Protanopia
#0043a8
Deuteranopia
#00556c
Tritanopia
#3f3f3f
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
9.17:1
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
2.29:1

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
##3737AA
Display P3
Display P3
color(display-p3 0.2157 0.2157 0.6417)
P3 has subtle headroomOKLCH chroma 0.178

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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