Utilitarian Tonbo
Utilitarian Tonbo (#6680A3) is a true 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 (214°, 25%, 52%) 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.
Etymology
Latin ūtilitās, usefulness — adjectival suffix -ian. As a color modifier, utilitarian implies a clear-and-purpose-fit-and-stripped-down quality, the crisp color of Shaker-and-Quaker anti-ornamental functional-and-no-frills craft tradition. Sits at the crisp-and-functional end of the grid, parallel to functional and workmanlike in usage.
The Japanese word for dragonfly — and tonbo-iro, the iridescent blue-green of dragonfly wing membranes. Tonbo is also a samurai-era heraldic motif representing victory (katsumushi, victory-insect). The color refers to a male blue-tail dragonfly's abdomen at rest: a saturated, slightly cool iridescent deep blue with the satin finish of structurally colored insect cuticle.
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.