#51CA99
Closest named color: Medium Aquamarine (#66CDAA). oklch(75.8% 0.131 163.4), rgb(81, 202, 153).
Aa
Black text reads best on this color (10.25:1).
About this color
#51CA99 is a medium-light, moderately saturated green. In OKLCH its lightness is 76%, its chroma 0.131 and its hue 163°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Medium Aquamarine (#66CDAA), ΔE 0.030 away. Black text reads best on it, at 10.25:1.
| Hue family | Greens |
| Lightness | medium-light (76%) |
| Chroma | moderately saturated (0.131) |
| Temperature | in between |
| Nearest name | Medium Aquamarine (#66CDAA) |
| Black text | 10.25:1 |
| White text | 2.04:1 |
Values
| HEX | #51CA99 |
| RGB | rgb(81, 202, 153) |
| HSL | hsl(156, 53%, 55%) |
| OKLCH | oklch(75.8% 0.131 163.4) |
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 #51CA99 | 2.04:1 | Fails | Lc -44.1 | Non-text elements, placeholder text |
| Black text on #51CA99 | 10.25:1 | AAA | Lc 64.4 | Content text, not long reading |
| #51CA99 text on white | 2.04:1 | Fails | Lc 39.6 | Non-text elements, placeholder text |
| #51CA99 text on black | 10.25:1 | AAA | Lc -62.8 | 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 400.
-
Step 50
50
#EFF8F3
oklch(97.1% 0.012 162.1)
-
Step 100
100
#DCEFE5
oklch(93.5% 0.024 163.1)
-
Step 200
200
#BFE3D1
oklch(88.5% 0.045 163.7)
-
Step 300
300
#8FD2B2
oklch(81% 0.082 163.2)
-
Step 400
400 (this color)
#51CA99
oklch(75.8% 0.131 163.4)
-
Step 500
500
#00A272
oklch(63% 0.135 163.5)
-
Step 600
600
#00885F
oklch(55.5% 0.119 163.5)
-
Step 700
700
#007350
oklch(49.2% 0.105 163.6)
-
Step 800
800
#005E41
oklch(42.7% 0.091 163.9)
-
Step 900
900
#004F35
oklch(37.8% 0.082 162.9)
-
Step 950
950
#002F1E
oklch(27% 0.058 163)
#51CA99 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) | #C7BC96 | 0.128 |
| Deuteranopia (no green cones) | #B6B09C | 0.124 |
| Tritanopia (no blue cones) | #03CABC | 0.052 |
| Achromatopsia (no color) | #B5B5B5 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #51CA99
#51CA99
oklch(75.8% 0.131 163.4)
- #EA8DC5
#EA8DC5
oklch(75.7% 0.131 343.8)
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 #51CA99, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Medium Aquamarine #66CDAA ΔE 0.030
- Greenblue #23C48B ΔE 0.035
- Emerald #06D6A0 ΔE 0.036
- Soft Green #6FC276 ΔE 0.044
- Green Blue #01C08D ΔE 0.046
- Dark Mint #48C072 ΔE 0.053
- Seafoam Blue #78D1B6 ΔE 0.056
- Seaweed #18D17B ΔE 0.057
Use #51CA99 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.