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Combustive Oxford

#518cfd
Notes

Combustive Oxford (#518CFD) is a true azure with a neon character. It sits at the high-saturation edge of its family. Use it sparingly, as signage, accent, or highlight against darker surfaces. Its HSL profile (219°, 98%, 65%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#518cfd
RGB
rgb(81, 140, 253)
HSL
hsl(219, 98%, 65%)
HWB
hwb(219 32% 1%)
OKLCH
oklch(65.7% 0.179 262.0)
P3
color(display-p3 0.3722 0.5432 0.9615)
HSV
hsv(219, 68%, 99%)
LAB
lab(59.52% 16.77 -61.99)
LCH
lch(59.52% 64.22 285.14)
CMYK
cmyk(68%, 45%, 0%, 1%)

Etymology

Combustive
adjective

Latin combūstus, burnt — adjectival suffix -ive, derived from com-burere (to burn-up). As a color modifier, combustive implies a saturated-and-burning-active quality, the bright color of blast-furnace-and-foundry combustion-chamber emission. Sits at the bright-and-warm end of the grid, parallel to fiery and blazing in usage.

Oxford
noun

The athletic blue of the University of Oxford — adopted alongside Cambridge's lighter blue in the 1820s, when the two universities first began racing crews against each other on the Thames. The color refers to an Oxford-blue rowing jersey: a saturated, slightly muted deep blue with the matte finish of melton wool. Deeper than navy, cooler than royal, with the rivalrous heraldic weight of a color paired with its institutional opposite.

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.

#518cfd
Original
#5398ff
Protanopia
#3288fb
Deuteranopia
#00a6b8
Tritanopia
#888888
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
3.22:1
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
6.52:1

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
##518CFD
Display P3
Display P3
color(display-p3 0.3722 0.5432 0.9615)
P3 has subtle headroomOKLCH chroma 0.179

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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