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Frank Aconitum

#538acf
Notes

Frank Aconitum (#538ACF) is a true azure 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 (213°, 56%, 57%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#538acf
RGB
rgb(83, 138, 207)
HSL
hsl(213, 56%, 57%)
HWB
hwb(213 33% 19%)
OKLCH
oklch(62.6% 0.120 254.9)
P3
color(display-p3 0.3754 0.5357 0.7906)
HSV
hsv(213, 60%, 81%)
LAB
lab(56.60% 2.71 -41.03)
LCH
lch(56.60% 41.12 273.77)
CMYK
cmyk(60%, 33%, 0%, 19%)

Etymology

Frank
adjective

From the Old French franc, free, sincere — used as a color modifier since the seventeenth century for hues that read as direct and unhedged. Frank red, frank brown: moderate-to-high saturation combined with optical directness. Sits at the crisp-bucket alongside direct and honest.

Aconitum
noun

The genus Aconitummonkshood, the highly toxic European perennial whose deep blue-purple hooded flowers contain aconitine alkaloid (poisonous enough to kill on skin contact). The color refers to a fresh A. napellus in late summer: a saturated, slightly cool deep blue-violet with the matte finish of helmet-shaped 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.

#538acf
Original
#6d8ed2
Protanopia
#5d82ce
Deuteranopia
#009aa3
Tritanopia
#838383
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).
AA Largeon White
3.56:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAon Black
5.90:1

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
##538ACF
Display P3
Display P3
color(display-p3 0.3754 0.5357 0.7906)
P3 has subtle headroomOKLCH chroma 0.120

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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