Robust Spruce
Robust Spruce (#309B1E) is a true green 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 (111°, 68%, 36%) 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 violet. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
From the Latin robustus, of oak — implying strength combined with substance. As a color modifier, robust describes saturation combined with body: a robust burgundy, a robust olive. Sits in the bold-and-warm corner alongside strong and solid, with the slightly textural implication of a color that has substance behind the pigment.
The genus Picea, the spruces of the boreal and montane forests — Sitka, Norway, blue, white, black — the conifer that frames timberline across the northern hemisphere. The color refers to fresh spruce needles: a deep, slightly blue-shifted green with the matte finish of resin-coated foliage. Cooler than fern, warmer than teal, with the resinous cold-air association of a high-altitude or high-latitude evergreen.
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.