#256E66
Closest named color: Dark Aquamarine (#017371). oklch(49.1% 0.072 185), rgb(37, 110, 102).
Aa
White text reads best on this color (5.99:1).
About this color
#256E66 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 49%, its chroma 0.072 and its hue 185°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Aquamarine (#017371), ΔE 0.021 away. White text reads best on it, at 5.99:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (49%) |
| Chroma | moderately saturated (0.072) |
| Temperature | cool |
| Nearest name | Dark Aquamarine (#017371) |
| Black text | 3.50:1 |
| White text | 5.99:1 |
Values
| HEX | #256E66 |
| RGB | rgb(37, 110, 102) |
| HSL | hsl(173, 50%, 29%) |
| OKLCH | oklch(49.1% 0.072 185) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #256E66 | 5.99:1 | AA | Lc -84.9 | Fine for body text |
| Black text on #256E66 | 3.50:1 | AA large text | Lc 24.3 | Dividers and decoration only |
| #256E66 text on white | 5.99:1 | AA | Lc 79.7 | Fine for body text |
| #256E66 text on black | 3.50:1 | AA large text | Lc -22.1 | Dividers and decoration only |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 700.
-
Step 50
50
#F2F6F6
oklch(97% 0.004 197.1)
-
Step 100
100
#E3ECEB
oklch(93.6% 0.01 189.1)
-
Step 200
200
#CCDEDB
oklch(88.6% 0.02 184.9)
-
Step 300
300
#A8C8C3
oklch(80.8% 0.035 185)
-
Step 400
400
#78ACA5
oklch(70.6% 0.056 185.6)
-
Step 500
500
#53988F
oklch(63.2% 0.072 184.7)
-
Step 600
600
#348279
oklch(55.6% 0.077 184.9)
-
Step 700
700 (this color)
#256E66
oklch(49.1% 0.072 185)
-
Step 800
800
#215A53
oklch(42.8% 0.06 184.2)
-
Step 900
900
#214A45
oklch(37.8% 0.047 185)
-
Step 950
950
#142B28
oklch(26.9% 0.03 184.8)
#256E66 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #686866 | 0.076 |
| Deuteranopia (no green cones) | #5E6067 | 0.073 |
| Tritanopia (no blue cones) | #00706B | 0.014 |
| Achromatopsia (no color) | #636363 | 0.073 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #256E66
#256E66
oklch(49.1% 0.072 185)
- #834F5B
#834F5B
oklch(49.1% 0.071 5.1)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #256E66, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Aquamarine #017371 ΔE 0.021
- Deep Turquoise #017374 ΔE 0.023
- Dark Aqua #05696B ΔE 0.025
- Dark Green Blue #1F6357 ΔE 0.038
- Bluegreen #017A79 ΔE 0.039
- Deep Aqua #08787F ΔE 0.042
- Petrol #005F6A ΔE 0.056
- Teal #008080 ΔE 0.058
Use #256E66 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.