Effective Tao Kingfisher
Effective Tao Kingfisher (#1D6A2A) is a deep 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 (130°, 57%, 26%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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
Latin effectīvus, productive — adjectival suffix -ive. As a color modifier, effective implies a clear-and-purpose-achieving quality where the hue carries the visual register of successful-task-completion design-element. Sits at the crisp-and-functional end of the grid, parallel to practical and useful in usage.
Chinese 道, the-Way. As a color modifier, tao implies a Daoist-and-naturalistic quality, the visual register of Chinese-Daoist-Wǔdāng-Mountain Daoist hand-built rock-and-pine-tree-and-incense-burner mountain-temple surfaces under Wǔdāng-Mountain-and-Mount-Hua Daoist-mountain-temple mist-and-pine light. Sits at the modifier-and-cultural end of the grid, parallel to zen and sufi in usage.
The family Alcedinidae — particularly Alcedo atthis, the European common kingfisher whose iridescent turquoise-blue plumage gives the color its name. The color refers to a male European kingfisher's wing: a saturated, slightly cool deep blue-green with the iridescent satin finish of structurally colored feathers.
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.