colors
Back to gallery

Surveyed Apse Lagoon

#409b9f
Notes

Surveyed Apse Lagoon (#409B9F) is a true cyan 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 (183°, 43%, 44%) places it in the balanced 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#409b9f
RGB
rgb(64, 155, 159)
HSL
hsl(183, 43%, 44%)
HWB
hwb(183 25% 38%)
OKLCH
oklch(63.7% 0.086 199.2)
P3
color(display-p3 0.3498 0.6000 0.6183)
HSV
hsv(183, 60%, 62%)
LAB
lab(59.01% -25.45 -10.19)
LCH
lch(59.01% 27.42 201.81)
CMYK
cmyk(60%, 3%, 0%, 38%)

Etymology

Surveyed
adjective

Old French surveer, to look upon — past-participle of survey. As a color modifier, surveyed implies a clear-and-measured-and-coordinated quality, the crisp color of Mason-Dixon-Line-and-Royal-Navy-Hydrographic scientific-and-cadastral land-and-sea surveying tradition. Sits at the crisp-and-mapped end of the grid, parallel to mapped and plotted in usage.

Apse
modifier

Latin absis, vault / arch-recess. As a color modifier, apse implies a semicircular-vaulted-altar-end quality, the visual register of Romanesque-and-Byzantine-cathedral hand-laid mosaic-and-fresco-decorated semicircular altar-end vaulted-apse architectural surfaces under candle-and-incense apse light. Sits at the modifier-and-architecture end of the grid, parallel to nave and aisle in usage.

Lagoon
noun

A shallow body of saltwater partially or fully enclosed by a barrier — coral atoll lagoons in the Pacific, Venice's Laguna Veneta, the Florida Keys' backcountry. The color refers to the average reflectance of a calm tropical lagoon at midday: a saturated, slightly muted blue-green with the optical clarity of shallow water over white sand. Brighter than reef, cooler than aquamarine, with the postcard weight of a Pacific atoll seen from above.

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.

#409b9f
Original
#91949f
Protanopia
#8289a0
Deuteranopia
#00a09c
Tritanopia
#888888
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
3.28:1
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
6.41:1

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
##409B9F
Display P3
Display P3
color(display-p3 0.3498 0.6000 0.6183)
P3 has subtle headroomOKLCH chroma 0.086

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.

Related Colors

Canvas