colors
Back to gallery

Functional Plumbago

#55ace1
Notes

Functional Plumbago (#55ACE1) is a true azure with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (203°, 70%, 61%) 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
#55ace1
RGB
rgb(85, 172, 225)
HSL
hsl(203, 70%, 61%)
HWB
hwb(203 33% 12%)
OKLCH
oklch(71.2% 0.114 238.0)
P3
color(display-p3 0.4209 0.6666 0.8634)
HSV
hsv(203, 62%, 88%)
LAB
lab(67.18% -10.39 -34.50)
LCH
lch(67.18% 36.03 253.24)
CMYK
cmyk(62%, 24%, 0%, 12%)

Etymology

Functional
adjective

Latin fūnctiō, performance — adjectival suffix -al. As a color modifier, functional implies a clear-and-purpose-fit-and-utilitarian quality, the crisp color of Mid-Century-Modern and Bauhaus form-follows-function design-aesthetic. Sits at the crisp-and-functional end of the grid, parallel to practical and utilitarian in usage.

Plumbago
noun

Plumbago auriculata, the South African shrub whose pale-blue five-petaled flowers cluster on stems through summer. The Latin name traces to plumbum, lead, for the plant's purported ability to cure lead-related skin afflictions. The color refers to a fresh plumbago bloom: a soft, slightly violet-shifted very pale blue with the matte finish of a five-petaled flower. Lighter than larkspur, cooler than periwinkle.

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.

#55ace1
Original
#93abe3
Protanopia
#809de0
Deuteranopia
#00b9be
Tritanopia
#9d9d9d
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).
Failon White
2.51:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAAon Black
8.37:1

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
##55ACE1
Display P3
Display P3
color(display-p3 0.4209 0.6666 0.8634)
P3 has subtle headroomOKLCH chroma 0.114

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