Practical Nebula Topaz
Practical Nebula Topaz (#13C4B7) is a true cyan with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (176°, 82%, 42%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. 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
Greek praktikós, practical — adjectival suffix -al. As a color modifier, practical implies a clear-and-purpose-fit-and-everyday quality where the hue carries the visual register of Shaker-and-Quaker utilitarian-and-functional everyday-life craft. Sits at the crisp-and-functional end of the grid, parallel to functional and workmanlike in usage.
Latin nebula, mist-or-cloud. As a color modifier, nebula implies a glowing-cloud-and-stellar-cradle quality, the visual register of Orion-and-Eagle-Nebula hand-glowing-cloud-and-stellar-cradle Orion-and-Eagle-and-Crab-Nebula nebula-and-glowing-cloud-and-stellar-cradle surfaces under Orion-and-Eagle-and-Crab-Nebula Hubble-and-James-Webb-deep-field stellar-cradle-light. Sits at the modifier-and-cosmic end of the grid, parallel to plasma and meteor in usage.
A fluorine aluminum silicate gem, hardness 8 on the Mohs scale, mined for centuries in Ouro Preto, Brazil. Imperial topaz is the prized variety: a warm, slightly pink-shifted gold-orange with the high refractive index of a quality cut stone. Cooler than amber, brighter than honey, with the gem's signature internal fire when held to light. Named for the island of Topazos in the Red Sea, though that source produced peridot instead.
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.