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Praetorian Stratus

#3f7ddb
Notes

Praetorian Stratus (#3F7DDB) 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 (216°, 68%, 55%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#3f7ddb
RGB
rgb(63, 125, 219)
HSL
hsl(216, 68%, 55%)
HWB
hwb(216 25% 14%)
OKLCH
oklch(59.6% 0.157 258.6)
P3
color(display-p3 0.3081 0.4844 0.8327)
HSV
hsv(216, 71%, 86%)
LAB
lab(52.77% 11.34 -53.93)
LCH
lch(52.77% 55.11 281.88)
CMYK
cmyk(71%, 43%, 0%, 14%)

Etymology

Praetorian
adjective

Latin praetōriānus, of the praetor — adjectival suffix, referring to the Roman-Imperial elite guard-cohorts. As a color modifier, praetorian implies a saturated-and-elite-and-imperial-guard quality, the deep-rich color of Roman-Praetorian-Guard elite-imperial-bodyguard scarlet-tunic-and-bronze-armor military-formation. Sits at the bold-and-formal end of the grid, parallel to spartan and imperial.

Stratus
noun

The Latin meteorological term for layer cloud — the low, gray-blue overcast clouds that cover the entire sky in mid-latitude winters. Stratus refers to a fully developed stratus deck on a North Sea winter morning: a soft, slightly muted deep blue-gray with the optical density of homogeneous low cloud.

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.

#3f7ddb
Original
#4f86df
Protanopia
#3377d9
Deuteranopia
#0093a1
Tritanopia
#777777
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
4.06:1
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
5.17:1

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
##3F7DDB
Display P3
Display P3
color(display-p3 0.3081 0.4844 0.8327)
P3 has subtle headroomOKLCH chroma 0.157

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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