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Firm Blueprint

#378ef3
Notes

Firm Blueprint (#378EF3) 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 (212°, 89%, 58%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#378ef3
RGB
rgb(55, 142, 243)
HSL
hsl(212, 89%, 58%)
HWB
hwb(212 22% 5%)
OKLCH
oklch(64.5% 0.172 254.6)
HSV
hsv(212, 77%, 95%)
LAB
lab(58.63% 8.71 -57.96)
LCH
lch(58.63% 58.61 278.55)
CMYK
cmyk(77%, 42%, 0%, 5%)

Etymology

Firm
adjective

Latin firmus, strong / stable — sharing root with English farm (originally a fixed-yearly-rental). As a color modifier, firm implies a saturated-and-resolute quality where the hue holds its visual position without wavering. Sits at the bold-and-firm end of the grid, parallel to steadfast and unwavering in usage.

Blueprint
noun

The cyanotype reproduction process — invented by John Herschel in 1842 — used for architectural and engineering drawings until digital reproduction replaced it in the late twentieth century. Blueprint color refers to a fresh cyanotype print: a saturated, slightly cool deep blue with the matte finish of iron-cyanide-on-paper.

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.

#378ef3
Original
#5c96f7
Protanopia
#3a85f1
Deuteranopia
#00a6b5
Tritanopia
#838383
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
3.32:1
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
6.33:1

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