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Calm Reservoir

#537f98
Notes

Calm Reservoir (#537F98) is a true azure with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (202°, 29%, 46%) places it in the muted band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. 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
#537f98
RGB
rgb(83, 127, 152)
HSL
hsl(202, 29%, 46%)
HWB
hwb(202 33% 40%)
OKLCH
oklch(57.4% 0.062 234.3)
P3
color(display-p3 0.3637 0.4935 0.5863)
HSV
hsv(202, 45%, 60%)
LAB
lab(51.02% -8.14 -18.16)
LCH
lch(51.02% 19.90 245.86)
CMYK
cmyk(45%, 16%, 0%, 40%)

Etymology

Calm
adjective

Latin calma, heat of the day — paradoxically drifted in Italian to mean stillness. Used as a color modifier since the seventeenth century for hues that read as untroubled. Calm blue, calm gray: moderate saturation combined with optical quiet. Sits at the crisp-bucket near quiet and steady.

Reservoir
noun

A constructed body of water — particularly the dam-impounded reservoirs of arid-region water supply: Lake Mead, Hetch Hetchy, Lake Powell. Reservoir color refers to mid-depth Lake Mead water: a saturated, slightly cool deep blue with the optical depth of stored desert water.

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.

#537f98
Original
#737e99
Protanopia
#6a7698
Deuteranopia
#358687
Tritanopia
#777777
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
4.32:1
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
4.86:1

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
##537F98
Display P3
Display P3
color(display-p3 0.3637 0.4935 0.5863)
Inside sRGBOKLCH chroma 0.062

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.

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