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Tough Manchuria

#4278fd
Notes

Tough Manchuria (#4278FD) 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 (223°, 98%, 63%) 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
#4278fd
RGB
rgb(66, 120, 253)
HSL
hsl(223, 98%, 63%)
HWB
hwb(223 26% 1%)
OKLCH
oklch(61.0% 0.207 264.4)
P3
color(display-p3 0.3097 0.4654 0.9588)
HSV
hsv(223, 74%, 99%)
LAB
lab(53.69% 27.04 -71.42)
LCH
lch(53.69% 76.37 290.73)
CMYK
cmyk(74%, 53%, 0%, 1%)

Etymology

Tough
adjective

Old English tōh, firm / tenacious — sharing root with German zäh. As a color modifier, tough implies a saturated-and-resilient quality where the hue resists fading-and-modulation through its strong pigmentation. Sits at the bold-and-resilient end of the grid, parallel to rugged and hardy in usage.

Manchuria
noun

The northeastern Chinese region — historically the homeland of the Manchu people — and the deep blue of Manchurian winter sky and the Songhua River at Harbin. Manchuria refers to a Harbin Ice Festival ice sculpture in Manchurian midwinter sky: a saturated, slightly cool deep blue.

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.

#4278fd
Original
#0f89ff
Protanopia
#0078fa
Deuteranopia
#0098af
Tritanopia
#767676
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
3.94:1
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
5.34:1

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
##4278FD
Display P3
Display P3
color(display-p3 0.3097 0.4654 0.9588)
P3 has visible headroomOKLCH chroma 0.207

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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