#128E51
Closest named color: Sea Green (#2E8B57). oklch(57% 0.137 154.5), rgb(18, 142, 81).
Aa
Black text reads best on this color (5.01:1).
About this color
#128E51 is a medium-dark, moderately saturated green. In OKLCH its lightness is 57%, its chroma 0.137 and its hue 155°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Sea Green (#2E8B57), ΔE 0.019 away. Black text reads best on it, at 5.01:1.
| Hue family | Greens |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.137) |
| Temperature | in between |
| Nearest name | Sea Green (#2E8B57) |
| Black text | 5.01:1 |
| White text | 4.18:1 |
Values
| HEX | #128E51 |
| RGB | rgb(18, 142, 81) |
| HSL | hsl(150, 78%, 31%) |
| OKLCH | oklch(57% 0.137 154.5) |
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 #128E51 | 4.18:1 | AA large text | Lc -73.8 | Content text, not long reading |
| Black text on #128E51 | 5.01:1 | AA | Lc 35.7 | Non-text elements, placeholder text |
| #128E51 text on white | 4.18:1 | AA large text | Lc 68.3 | Content text, not long reading |
| #128E51 text on black | 5.01:1 | AA | Lc -33.3 | Non-text elements, placeholder text |
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 600.
-
Step 50
50
#F1F7F3
oklch(97.1% 0.008 157.1)
-
Step 100
100
#E1EEE5
oklch(93.7% 0.018 155.8)
-
Step 200
200
#C8E0CF
oklch(88.4% 0.034 154.8)
-
Step 300
300
#A2CDAF
oklch(80.9% 0.062 154.4)
-
Step 400
400
#6CB385
oklch(70.7% 0.099 154.6)
-
Step 500
500
#3E9F66
oklch(63% 0.126 154.5)
-
Step 600
600 (this color)
#128E51
oklch(57% 0.137 154.5)
-
Step 700
700
#007440
oklch(49.1% 0.122 154.8)
-
Step 800
800
#025F33
oklch(42.7% 0.106 154.4)
-
Step 900
900
#134E2D
oklch(37.7% 0.082 154.4)
-
Step 950
950
#0E2E1B
oklch(27.1% 0.052 154.7)
#128E51 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) | #8E824D | 0.121 |
| Deuteranopia (no green cones) | #807855 | 0.118 |
| Tritanopia (no blue cones) | #008C7F | 0.069 |
| Achromatopsia (no color) | #7C7C7C | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #128E51
#128E51
oklch(57% 0.137 154.5)
- #A75498
#A75498
oklch(57% 0.139 334.5)
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 #128E51, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sea Green #2E8B57 ΔE 0.019
- Viridian #1E9167 ΔE 0.031
- Kelley Green #009337 ΔE 0.038
- Jungle Green #048243 ΔE 0.038
- Light Forest Green #4F9153 ΔE 0.041
- Fern Green #548D44 ΔE 0.042
- Forest Green #228B22 ΔE 0.046
- Irish Green #019529 ΔE 0.053
Use #128E51 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.