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Sure Bay

#045d70
Notes

Sure Bay (#045D70) is a deep cyan with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (191°, 93%, 23%) places it in the highly saturated band at a dark 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#045d70
RGB
rgb(4, 93, 112)
HSL
hsl(191, 93%, 23%)
HWB
hwb(191 2% 56%)
OKLCH
oklch(44.2% 0.078 218.4)
P3
color(display-p3 0.1536 0.3589 0.4308)
HSV
hsv(191, 96%, 44%)
LAB
lab(36.03% -15.81 -17.36)
LCH
lch(36.03% 23.48 227.68)
CMYK
cmyk(96%, 17%, 0%, 56%)

Etymology

Sure
adjective

Old French seur, certain — used as a color modifier since the medieval period for hues that read as confident and stable. Sure red, sure blue: moderate saturation combined with optical commitment. Sits at the crisp-bucket center alongside steady and true.

Bay
noun

A body of water partially enclosed by land — Chesapeake, Tokyo, Hudson, Naples. The color refers to the average reflectance of a temperate bay on a clear day: a saturated, slightly muted blue with the optical depth of mid-salinity water. Cooler than peacock, warmer than navy, with the geographic specificity of a word that names the largest indentations in every world coastline.

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.

#045d70
Original
#515a71
Protanopia
#445170
Deuteranopia
#006363
Tritanopia
#4b4b4b
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).
AAAon White
7.49:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon Black
2.80:1

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
##045D70
Display P3
Display P3
color(display-p3 0.1536 0.3589 0.4308)
Inside sRGBOKLCH chroma 0.078

This color sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.

Related Colors

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