Functional Fluff Denim
Functional Fluff Denim (#255C87) is a deep azure with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (206°, 57%, 34%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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.
Etymology
Latin fūnctiō, performance — adjectival suffix -al. As a color modifier, functional implies a clear-and-purpose-fit-and-utilitarian quality, the crisp color of Mid-Century-Modern and Bauhaus form-follows-function design-aesthetic. Sits at the crisp-and-functional end of the grid, parallel to practical and utilitarian in usage.
Imitative-onomatopoeic origin, attested c. 1790. As a color modifier, fluff implies a soft-puffed-and-airy quality, the visual register of cotton-and-down-and-wool-fluff hand-carded-and-puffed cotton-and-down-and-wool-fluff hand-carded-and-puffed-fluff surfaces under hand-carded-and-puffed cotton-and-down-and-wool-fluff working-light. Sits at the modifier-and-texture end of the grid, parallel to down and fuzz in usage.
The diagonal-twill cotton fabric originally woven in Nîmes, France — serge de Nîmes, contracted to denim — and dyed with indigo since at least the eighteenth century. The color refers to a worn but un-faded pair of raw denim jeans: a saturated, slightly muted blue with the matte finish of cotton fiber that has absorbed dye through generations of weft and warp. Cooler than royal, warmer than navy.
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
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.
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.