Tough Lime
Tough Lime (#5D9D1A) is a true lime 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 (89°, 72%, 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 indigo. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English tōh, firm / tenacious — sharing root with German zäh. As a color modifier, tough implies a saturated-and-resilient quality where the hue resists fading-and-modulation through its strong pigmentation. Sits at the bold-and-resilient end of the grid, parallel to rugged and hardy in usage.
Citrus aurantiifolia and its key-lime cousin — small, intensely sour green citrus carried by Arab traders from Southeast Asia to the Mediterranean by the eleventh century, then to the Caribbean with Columbus. The color refers to the skin of a fully ripe Persian lime: a saturated, slightly yellow-shifted green with the matte finish of citrus rind. Cooler than chartreuse, sharper than sage, with the same chlorophyll the fruit loses if left to ripen to yellow.
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.