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Fortified Thistle

#633798
Notes

Fortified Thistle (#633798) is a true indigo 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 (267°, 47%, 41%) 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 lime. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#633798
RGB
rgb(99, 55, 152)
HSL
hsl(267, 47%, 41%)
HWB
hwb(267 22% 40%)
OKLCH
oklch(44.2% 0.153 301.2)
P3
color(display-p3 0.3646 0.2240 0.5756)
HSV
hsv(267, 64%, 60%)
LAB
lab(33.25% 39.79 -46.00)
LCH
lch(33.25% 60.83 310.86)
CMYK
cmyk(35%, 64%, 0%, 40%)

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.

Thistle
noun

The thistles — Onopordum, Cirsium, Carduus — spiny composite-family perennials whose tufted purple flower heads adorn the Scottish national emblem and uncountable European pasture margins. The color refers to a fresh thistle flower at peak bloom: a soft, slightly red-shifted pale purple with the matte finish of tufted florets. Lighter than heather, warmer than lavender, with the heraldic weight of a flower that defends itself with thorns.

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.

#633798
Original
#004e9b
Protanopia
#144e96
Deuteranopia
#584c62
Tritanopia
#474747
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
8.30:1
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
2.53:1

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
##633798
Display P3
Display P3
color(display-p3 0.3646 0.2240 0.5756)
P3 has subtle headroomOKLCH chroma 0.153

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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