#21B137
Closest named color: Shamrock (#01B44C). oklch(66.4% 0.199 144.7), rgb(33, 177, 55).
Aa
Black text reads best on this color (7.40:1).
About this color
#21B137 is a medium-light, vivid green. In OKLCH its lightness is 66%, its chroma 0.199 and its hue 145°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Shamrock (#01B44C), ΔE 0.017 away. Black text reads best on it, at 7.40:1.
| Hue family | Greens |
| Lightness | medium-light (66%) |
| Chroma | vivid (0.199) |
| Temperature | in between |
| Nearest name | Shamrock (#01B44C) |
| Black text | 7.40:1 |
| White text | 2.83:1 |
Values
| HEX | #21B137 |
| RGB | rgb(33, 177, 55) |
| HSL | hsl(129, 69%, 41%) |
| OKLCH | oklch(66.4% 0.199 144.7) |
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 #21B137 | 2.83:1 | Fails | Lc -59.0 | Large or bold text, headings |
| Black text on #21B137 | 7.40:1 | AAA | Lc 50.3 | Large or bold text, headings |
| #21B137 text on white | 2.83:1 | Fails | Lc 53.8 | Large or bold text, headings |
| #21B137 text on black | 7.40:1 | AAA | Lc -48.1 | 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 500.
-
Step 50
50
#F0F8F0
oklch(97.1% 0.014 145.5)
-
Step 100
100
#DFEFDF
oklch(93.6% 0.027 145.4)
-
Step 200
200
#C4E3C3
oklch(88.5% 0.054 144.3)
-
Step 300
300
#99D299
oklch(81% 0.099 144.6)
-
Step 400
400
#5AB95F
oklch(70.6% 0.156 144.7)
-
Step 500
500 (this color)
#21B137
oklch(66.4% 0.199 144.7)
-
Step 600
600
#008C21
oklch(55.6% 0.177 144.7)
-
Step 700
700
#00761B
oklch(49.2% 0.156 144.8)
-
Step 800
800
#006114
oklch(42.8% 0.136 144.7)
-
Step 900
900
#00510F
oklch(37.8% 0.12 144.7)
-
Step 950
950
#023008
oklch(27% 0.082 145)
#21B137 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) | #B4A026 | 0.147 |
| Deuteranopia (no green cones) | #A59543 | 0.148 |
| Tritanopia (no blue cones) | #00AC98 | 0.124 |
| Achromatopsia (no color) | #999999 | 0.200 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21B137
#21B137
oklch(66.4% 0.199 144.7)
- #CD60D6
#CD60D6
oklch(66.5% 0.199 324.5)
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 #21B137, closest first.
No curated palette has a color within ΔE 0.04 of #21B137.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Shamrock #01B44C ΔE 0.017
- Kelly Green #02AB2E ΔE 0.020
- Medium Green #39AD48 ΔE 0.025
- Leafy Green #51B73B ΔE 0.034
- Grass #5CAC2D ΔE 0.035
- Leaf Green #5CA904 ΔE 0.037
- Mid Green #50A747 ΔE 0.044
- Shamrock Green #02C14D ΔE 0.045
Use #21B137 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.