Mellow Fog
Mellow Fog (#E4E5E9) is a soft blue with a pastel character. It reads calm and airy, with enough chroma to feel intentional rather than washed out. Its HSL profile (228°, 10%, 90%) places it in the muted band at a light lightness. It works as a background wash, large-area fill, or soft illustration tone. Add a darker ink of the same hue when you need type over it. For a confident two-color system, pair it with its complementary amber. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Middle English melwe, ripe, soft — used as a color modifier since the sixteenth century for hues that read as softened by ripening or aging. Mellow gold, mellow brown: moderate-to-low saturation combined with optical warmth. Sits across the hushed and neutral buckets alongside muted.
A dense suspension of water droplets at ground level — visibility under a kilometer, distinguishing it from mist. The color refers to a fully developed coastal fog at dawn: a soft, very pale slightly cool gray with the optical density of a thick water-droplet cloud. Cooler than mist, lighter than smoke, with the maritime weight of a phenomenon that defines San Francisco summers and the entire California coast.
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 exploreHarmonies
This color has effectively no chroma (OKLCH C = 0.005) — it’s on the grayscale axis. Hue rotations don’t change a grayscale color, so complementary, analogous, triadic, and split-complementary all reduce to the same value. They aren’t shown because four identical tiles would be misleading.
Accessibility
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.
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.
Wide gamut
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.
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.