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Fortified Lull Indigo

#6655ef
Notes

Fortified Lull Indigo (#6655EF) is a true blue with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (247°, 83%, 64%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. 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
#6655ef
RGB
rgb(102, 85, 239)
HSL
hsl(247, 83%, 64%)
HWB
hwb(247 33% 6%)
OKLCH
oklch(55.8% 0.221 281.5)
P3
color(display-p3 0.3892 0.3358 0.9037)
HSV
hsv(247, 64%, 94%)
LAB
lab(46.38% 48.47 -75.41)
LCH
lch(46.38% 89.65 302.73)
CMYK
cmyk(57%, 64%, 0%, 6%)

Etymology

Fortified
adjective

Latin fortificāre, to make strong — past-participle of fortify. As a color modifier, fortified implies a saturated-and-strengthened-and-defensive quality, the deep-rich color of Vauban-style military-fortification stone-and-earth rampart-and-bastion architecture. Sits at the bold-and-fortified end of the grid, parallel to bastioned and armored.

Lull
modifier

Middle English lullen, to-sing-to-sleep. As a color modifier, lull implies a hushed-and-pacified-and-cradled quality, the visual register of cradle-song-and-vesper-lull hand-cradled-and-rocked cradle-and-cot-and-crib hand-rocked-and-sung-to-lulled-and-cradled lulled-and-cradled surfaces under cradle-song-and-vesper hush-and-quiet-and-still bedside-and-nursery-light. Sits at the modifier-and-mood end of the grid, parallel to hush and soothe in usage.

Indigo
noun

Indigofera tinctoria, the South Asian legume whose leaves yield the deep blue dye that has clothed humanity for at least four thousand years — Egyptian linen, Mayan textile, the slave-grown plantations of Carolina. The color refers to a freshly indigo-dyed cotton thread: a saturated, slightly violet-shifted deep blue with the slight lustre of a fiber surface oxidized in air. Deeper than cobalt, cooler than royal.

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.

#6655ef
Original
#0073f4
Protanopia
#0068ec
Deuteranopia
#117c9b
Tritanopia
#646464
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).
AAon White
5.11:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
4.11:1

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
##6655EF
Display P3
Display P3
color(display-p3 0.3892 0.3358 0.9037)
P3 has visible headroomOKLCH chroma 0.221

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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