Frank Span Peacock
Frank Span Peacock (#90D3D4) is a true cyan 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 (181°, 44%, 70%) 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.
Etymology
From the Old French franc, free, sincere — used as a color modifier since the seventeenth century for hues that read as direct and unhedged. Frank red, frank brown: moderate-to-high saturation combined with optical directness. Sits at the crisp-bucket alongside direct and honest.
Old English spann, distance / period. As a color modifier, span implies a measured-stretch-of-time quality, the visual register of measured-and-bounded time-marked period-spanning bracket-of-time surfaces under measured-and-defined-period time-bounded mood-and-light. Sits at the modifier-and-time end of the grid, parallel to term and phase in usage.
Pavo cristatus, the Indian peafowl whose male displays the most elaborate sexual ornament in birds — a fan of two-meter eyespotted tail feathers in iridescent blue-green. The color is structural, not pigmented: created by interference patterns in the feather barbules. Peacock blue refers to the dominant body color: a saturated, slightly muted teal-blue with the optical depth of structural color. Cooler than persian, warmer than sapphire.
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.
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.