#21B491
Closest named color: Greeny Blue (#42B395). oklch(68.9% 0.128 171.4), rgb(33, 180, 145).
Aa
Black text reads best on this color (8.00:1).
About this color
#21B491 is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 69%, its chroma 0.128 and its hue 171°. Its hue sits on the cool side of the wheel. The nearest named color is Greeny Blue (#42B395), ΔE 0.017 away. Black text reads best on it, at 8.00:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (69%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Greeny Blue (#42B395) |
| Black text | 8.00:1 |
| White text | 2.62:1 |
Values
| HEX | #21B491 |
| RGB | rgb(33, 180, 145) |
| HSL | hsl(166, 69%, 42%) |
| OKLCH | oklch(68.9% 0.128 171.4) |
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 #21B491 | 2.62:1 | Fails | Lc -55.8 | Large or bold text, headings |
| Black text on #21B491 | 8.00:1 | AAA | Lc 53.3 | Large or bold text, headings |
| #21B491 text on white | 2.62:1 | Fails | Lc 50.7 | Large or bold text, headings |
| #21B491 text on black | 8.00:1 | AAA | Lc -51.2 | Large or bold text, headings |
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 400.
-
Step 50
50
#EFF8F4
oklch(97.1% 0.011 167.8)
-
Step 100
100
#DBEFE8
oklch(93.5% 0.023 172.8)
-
Step 200
200
#BDE3D5
oklch(88.5% 0.044 170.9)
-
Step 300
300
#8AD2BA
oklch(80.9% 0.08 171.2)
-
Step 400
400 (this color)
#21B491
oklch(68.9% 0.128 171.4)
-
Step 500
500
#00A180
oklch(63.1% 0.123 171.4)
-
Step 600
600
#00876B
oklch(55.5% 0.108 171.4)
-
Step 700
700
#00725A
oklch(49.2% 0.096 171.5)
-
Step 800
800
#005D49
oklch(42.6% 0.083 171.6)
-
Step 900
900
#004E3D
oklch(37.8% 0.073 171.8)
-
Step 950
950
#002F23
oklch(27.2% 0.053 170.5)
#21B491 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) | #AEA78F | 0.131 |
| Deuteranopia (no green cones) | #9C9A93 | 0.126 |
| Tritanopia (no blue cones) | #00B6AA | 0.035 |
| Achromatopsia (no color) | #A0A0A0 | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21B491
#21B491
oklch(68.9% 0.128 171.4)
- #D678A4
#D678A4
oklch(68.9% 0.128 351.5)
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 #21B491, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Greeny Blue #42B395 ΔE 0.017
- Bluey Green #2BB179 ΔE 0.032
- Dark Seafoam #1FB57A ΔE 0.034
- Dark Seafoam Green #3EAF76 ΔE 0.035
- Green Blue #01C08D ΔE 0.037
- Green Teal #0CB577 ΔE 0.039
- Light Sea Green #20B2AA ΔE 0.039
- Topaz #13BBAF ΔE 0.042
Use #21B491 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.