Vitreous Smalt
Vitreous Smalt (#3A71B4) is a true azure 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 (213°, 51%, 47%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin vitreus, glass-like — derived from vitrum (glass). As a color modifier, vitreous implies a clear-and-glassy quality where the hue carries the optical clarity of polished crown-glass. Sits at the crisp-and-clear end of the grid, parallel to pellucid and crystalline in usage.
A cobalt-glass pigment — pulverized cobalt-tinted glass used in oil painting from the late medieval period through the eighteenth century. Smalt was supplanted by Prussian blue and cobalt blue once those became commercially available. The color refers to fresh smalt pigment in oil: a saturated, slightly cool deep blue with the matte finish of glass-particle pigment.
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.