Thunderous Kvass
Thunderous Kvass (#5D0549) is a deep magenta with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (314°, 90%, 19%) places it in the highly saturated band at a dark 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 green. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English thunor, thunder — adjectival suffix -ous, sharing root with German Donner and Old Norse Þórr (Thor). As a color modifier, thunderous implies a deep-and-rumbling-and-imposing-cool quality, the dark cool-gray of cumulonimbus-tower-base storm-cloud directly overhead. Sits at the deep-and-turbulent end of the grid, parallel to stormy with auditory-resonance overtone.
Eastern European kvass — a low-alcohol fermented drink made from rye-bread and beet-or-fruit additions, particularly the deep-magenta beet-kvass of Russian and Ukrainian post (Lenten) traditions. Kvass color refers to a freshly poured Russian-style beet-kvass in a clear-glass beer-mug: a saturated, slightly cool deep magenta with the matte finish of betalain-pigmented fermented-beet liquor on a dark birch-bench tavern surface.
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.