#21756D
Closest named color: Dark Aquamarine (#017371). oklch(51.1% 0.079 185.8), rgb(33, 117, 109).
Aa
White text reads best on this color (5.48:1).
About this color
#21756D is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 51%, its chroma 0.079 and its hue 186°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Aquamarine (#017371), ΔE 0.015 away. White text reads best on it, at 5.48:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (51%) |
| Chroma | moderately saturated (0.079) |
| Temperature | cool |
| Nearest name | Dark Aquamarine (#017371) |
| Black text | 3.83:1 |
| White text | 5.48:1 |
Values
| HEX | #21756D |
| RGB | rgb(33, 117, 109) |
| HSL | hsl(174, 56%, 29%) |
| OKLCH | oklch(51.1% 0.079 185.8) |
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 #21756D | 5.48:1 | AA | Lc -82.4 | Fine for body text |
| Black text on #21756D | 3.83:1 | AA large text | Lc 27.0 | Dividers and decoration only |
| #21756D text on white | 5.48:1 | AA | Lc 77.1 | Fine for body text |
| #21756D text on black | 3.83:1 | AA large text | Lc -24.7 | 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
#F2F7F6
oklch(97.2% 0.005 183)
-
Step 100
100
#E2ECEB
oklch(93.5% 0.011 189.8)
-
Step 200
200
#CADEDB
oklch(88.5% 0.022 186)
-
Step 300
300
#A6C9C4
oklch(80.9% 0.038 185.9)
-
Step 400
400
#74ADA6
oklch(70.6% 0.061 186.2)
-
Step 500
500
#4B9990
oklch(63.1% 0.078 185.5)
-
Step 600
600
#28837A
oklch(55.5% 0.085 185.6)
-
Step 700
700 (this color)
#21756D
oklch(51.1% 0.079 185.8)
-
Step 800
800
#185A54
oklch(42.5% 0.065 186.3)
-
Step 900
900
#1C4A45
oklch(37.6% 0.051 185.6)
-
Step 950
950
#122C29
oklch(27.1% 0.033 185.7)
#21756D 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) | #6F6E6D | 0.085 |
| Deuteranopia (no green cones) | #63656E | 0.080 |
| Tritanopia (no blue cones) | #007872 | 0.012 |
| Achromatopsia (no color) | #696969 | 0.080 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21756D
#21756D
oklch(51.1% 0.079 185.8)
- #8D5360
#8D5360
oklch(51.3% 0.079 5.7)
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 #21756D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Aquamarine #017371 ΔE 0.015
- Deep Turquoise #017374 ΔE 0.018
- Bluegreen #017A79 ΔE 0.020
- Deep Aqua #08787F ΔE 0.027
- Teal #008080 ΔE 0.037
- Dark Aqua #05696B ΔE 0.041
- Ocean #017B92 ΔE 0.056
- Dark Green Blue #1F6357 ΔE 0.059
Use #21756D 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.