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Authoritative Ametrine

#851ba7
Notes

Authoritative Ametrine (#851BA7) is a true violet with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (285°, 72%, 38%) 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 green. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#851ba7
RGB
rgb(133, 27, 167)
HSL
hsl(285, 72%, 38%)
HWB
hwb(285 11% 35%)
OKLCH
oklch(46.9% 0.210 315.8)
P3
color(display-p3 0.4787 0.1446 0.6316)
HSV
hsv(285, 84%, 65%)
LAB
lab(35.13% 61.56 -51.80)
LCH
lch(35.13% 80.46 319.92)
CMYK
cmyk(20%, 84%, 0%, 35%)

Etymology

Authoritative
adjective

Latin auctōritāt-, authority — adjectival suffix -ive. As a color modifier, authoritative implies a saturated-and-formal-imperative quality where the hue carries decisional weight and institutional credibility. Sits at the bold-and-authoritative end of the grid, parallel to commanding and magisterial in usage.

Ametrine
noun

Naturally bicolored amethyst-citrine zoned quartz mined principally at the Anahí mine in eastern Bolivia. The deep-violet amethyst portion contrasts with the golden citrine zone in a single crystal. Ametrine color refers to the deep-violet amethyst zone of a polished Anahí-mine ametrine cabochon: a saturated, slightly cool deep violet with the glassy finish of iron-and-aluminum-substituted quartz under reflected light.

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.

#851ba7
Original
#004dab
Protanopia
#1555a4
Deuteranopia
#823e64
Tritanopia
#3c3c3c
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
7.74:1
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
2.71:1

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
##851BA7
Display P3
Display P3
color(display-p3 0.4787 0.1446 0.6316)
P3 has visible headroomOKLCH chroma 0.210

This color is chromatic enough that authoring it as P3 native (instead of clamping to sRGB) gives a perceptibly more saturated render on wide-gamut displays — modern Macs, iPhones, iPads, and most recent OLED laptops.

Related Colors

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