#21737B
Closest named color: Deep Aqua (#08787F). oklch(51.1% 0.077 204.6), rgb(33, 115, 123).
Aa
White text reads best on this color (5.52:1).
About this color
#21737B is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 51%, its chroma 0.077 and its hue 205°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Aqua (#08787F), ΔE 0.015 away. White text reads best on it, at 5.52:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (51%) |
| Chroma | moderately saturated (0.077) |
| Temperature | cool |
| Nearest name | Deep Aqua (#08787F) |
| Black text | 3.80:1 |
| White text | 5.52:1 |
Values
| HEX | #21737B |
| RGB | rgb(33, 115, 123) |
| HSL | hsl(185, 58%, 31%) |
| OKLCH | oklch(51.1% 0.077 204.6) |
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 #21737B | 5.52:1 | AA | Lc -82.6 | Fine for body text |
| Black text on #21737B | 3.80:1 | AA large text | Lc 26.8 | Dividers and decoration only |
| #21737B text on white | 5.52:1 | AA | Lc 77.3 | Fine for body text |
| #21737B text on black | 3.80:1 | AA large text | Lc -24.5 | 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
#F2F6F7
oklch(97% 0.004 214.3)
-
Step 100
100
#E2ECED
oklch(93.6% 0.011 204.1)
-
Step 200
200
#CADDDF
oklch(88.4% 0.021 204.4)
-
Step 300
300
#A6C8CC
oklch(80.9% 0.037 205.2)
-
Step 400
400
#74ACB2
oklch(70.8% 0.059 204.4)
-
Step 500
500
#4B979F
oklch(63.1% 0.076 204.5)
-
Step 600
600
#28818A
oklch(55.6% 0.082 204.8)
-
Step 700
700 (this color)
#21737B
oklch(51.1% 0.077 204.6)
-
Step 800
800
#18595F
oklch(42.7% 0.064 204)
-
Step 900
900
#1C494E
oklch(37.7% 0.049 205.2)
-
Step 950
950
#122B2E
oklch(27.1% 0.031 205.7)
#21737B 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) | #696E7C | 0.076 |
| Deuteranopia (no green cones) | #5C657B | 0.068 |
| Tritanopia (no blue cones) | #007875 | 0.023 |
| Achromatopsia (no color) | #696969 | 0.077 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21737B
#21737B
oklch(51.1% 0.077 204.6)
- #8D5450
#8D5450
oklch(51% 0.077 24.4)
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 #21737B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Aqua #08787F ΔE 0.015
- Deep Turquoise #017374 ΔE 0.017
- Dark Aquamarine #017371 ΔE 0.021
- Bluegreen #017A79 ΔE 0.024
- Ocean #017B92 ΔE 0.037
- Teal #008080 ΔE 0.038
- Dark Aqua #05696B ΔE 0.040
- Sea Blue #047495 ΔE 0.041
Use #21737B 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.