Bright Pondweed
Bright Pondweed (#66D78E) is a true green with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (141°, 59%, 62%) 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 magenta. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English beorht, shining, luminous — cognate with the German Bracht, splendor. Applied to color since at least the medieval period for hues that read as luminous: not just light in value but optically active, as if scattering more light back than a dimmer color of the same lightness would. Sits at the bright-bucket center alongside vivid and brilliant.
The genus Potamogeton — submerged aquatic plants of freshwater ponds and slow streams. The color refers to a clump of fresh pondweed seen through pond water: a soft, slightly cool deep yellow-green-blue with the optical complexity of submerged leaf scattering filtered sunlight.
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.