#40D188
Closest named color: Seaweed (#18D17B). oklch(76.7% 0.162 156.7), rgb(64, 209, 136).
Aa
Black text reads best on this color (10.69:1).
About this color
#40D188 is a medium-light, vivid green. In OKLCH its lightness is 77%, its chroma 0.162 and its hue 157°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Seaweed (#18D17B), ΔE 0.024 away. Black text reads best on it, at 10.69:1.
| Hue family | Greens |
| Lightness | medium-light (77%) |
| Chroma | vivid (0.162) |
| Temperature | in between |
| Nearest name | Seaweed (#18D17B) |
| Black text | 10.69:1 |
| White text | 1.96:1 |
Values
| HEX | #40D188 |
| RGB | rgb(64, 209, 136) |
| HSL | hsl(150, 61%, 54%) |
| OKLCH | oklch(76.7% 0.162 156.7) |
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 #40D188 | 1.96:1 | Fails | Lc -41.8 | Non-text elements, placeholder text |
| Black text on #40D188 | 10.69:1 | AAA | Lc 66.5 | Content text, not long reading |
| #40D188 text on white | 1.96:1 | Fails | Lc 37.4 | Non-text elements, placeholder text |
| #40D188 text on black | 10.69:1 | AAA | Lc -65.0 | Content text, not long reading |
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 300.
-
Step 50
50
#EAFAF0
oklch(97.1% 0.021 158.6)
-
Step 100
100
#D2F4DD
oklch(93.6% 0.047 155.8)
-
Step 200
200
#A8ECC1
oklch(88.6% 0.091 156.3)
-
Step 300
300 (this color)
#40D188
oklch(76.7% 0.162 156.7)
-
Step 400
400
#00BF74
oklch(70.8% 0.169 156.8)
-
Step 500
500
#00A462
oklch(63.2% 0.152 156.5)
-
Step 600
600
#008A52
oklch(55.7% 0.134 156.6)
-
Step 700
700
#007444
oklch(49.2% 0.118 156.6)
-
Step 800
800
#005F37
oklch(42.7% 0.102 156.7)
-
Step 900
900
#004F2D
oklch(37.6% 0.09 156.8)
-
Step 950
950
#002F19
oklch(26.9% 0.064 157.1)
#40D188 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) | #D0C183 | 0.147 |
| Deuteranopia (no green cones) | #BDB48D | 0.143 |
| Tritanopia (no blue cones) | #00CFBE | 0.076 |
| Achromatopsia (no color) | #B9B9B9 | 0.163 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #40D188
#40D188
oklch(76.7% 0.162 156.7)
- #F288D9
#F288D9
oklch(76.6% 0.161 336.5)
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 #40D188, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Seaweed #18D17B ΔE 0.024
- Emerald #06D6A0 ΔE 0.030
- Aqua Green #12E193 ΔE 0.042
- Greenblue #23C48B ΔE 0.043
- Soft Green #6FC276 ΔE 0.046
- Dark Mint #48C072 ΔE 0.048
- Algae Green #21C36F ΔE 0.049
- Dark Mint Green #20C073 ΔE 0.054
Use #40D188 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.