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Plain Inlet

#51b5f2
Notes

Plain Inlet (#51B5F2) 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 (203°, 86%, 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#51b5f2
RGB
rgb(81, 181, 242)
HSL
hsl(203, 86%, 63%)
HWB
hwb(203 32% 5%)
OKLCH
oklch(73.9% 0.128 238.7)
P3
color(display-p3 0.4232 0.7010 0.9277)
HSV
hsv(203, 67%, 95%)
LAB
lab(70.32% -10.51 -38.90)
LCH
lch(70.32% 40.30 254.89)
CMYK
cmyk(67%, 25%, 0%, 5%)

Etymology

Plain
adjective

Latin planus, flat, level — used as a color modifier since the medieval period for hues that read as undecorated and direct. Plain white, plain blue: moderate saturation, no shift, no surface effect. Sits in the crisp-bucket center, with the implication of restraint rather than absence.

Inlet
noun

A narrow body of water leading inland from a sea or lake — particularly the saltwater inlets of the Pacific Northwest and Norway. Inlet color refers to a Pacific Northwest fjord inlet at midday: a saturated, slightly cool deep blue with the optical depth of cold-water tidal inlet.

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.

#51b5f2
Original
#99b5f5
Protanopia
#83a5f1
Deuteranopia
#00c4ca
Tritanopia
#a4a4a4
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).
Failon White
2.27:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAAon Black
9.24:1

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
##51B5F2
Display P3
Display P3
color(display-p3 0.4232 0.7010 0.9277)
P3 has subtle headroomOKLCH chroma 0.128

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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