#66C559
Closest named color: Apple (#6ECB3C). oklch(74.1% 0.172 141.3), rgb(102, 197, 89).
Aa
Black text reads best on this color (9.69:1).
About this color
#66C559 is a medium-light, vivid green. In OKLCH its lightness is 74%, its chroma 0.172 and its hue 141°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Apple (#6ECB3C), ΔE 0.033 away. Black text reads best on it, at 9.69:1.
| Hue family | Greens |
| Lightness | medium-light (74%) |
| Chroma | vivid (0.172) |
| Temperature | in between |
| Nearest name | Apple (#6ECB3C) |
| Black text | 9.69:1 |
| White text | 2.16:1 |
Values
| HEX | #66C559 |
| RGB | rgb(102, 197, 89) |
| HSL | hsl(113, 48%, 56%) |
| OKLCH | oklch(74.1% 0.172 141.3) |
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 #66C559 | 2.16:1 | Fails | Lc -47.0 | Large or bold text, headings |
| Black text on #66C559 | 9.69:1 | AAA | Lc 61.6 | Content text, not long reading |
| #66C559 text on white | 2.16:1 | Fails | Lc 42.3 | Non-text elements, placeholder text |
| #66C559 text on black | 9.69:1 | AAA | Lc -59.9 | 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
#F0F8EF
oklch(97.1% 0.015 142.2)
-
Step 100
100
#DFEFDC
oklch(93.5% 0.03 140.8)
-
Step 200
200
#C4E4BF
oklch(88.6% 0.06 141.3)
-
Step 300
300
#99D291
oklch(80.8% 0.107 141.5)
-
Step 400
400 (this color)
#66C559
oklch(74.1% 0.172 141.3)
-
Step 500
500
#20A600
oklch(63.1% 0.209 141.4)
-
Step 600
600
#1A8B00
oklch(55.5% 0.184 141.3)
-
Step 700
700
#147500
oklch(49% 0.162 141.3)
-
Step 800
800
#0F6000
oklch(42.6% 0.141 141.3)
-
Step 900
900
#0A5000
oklch(37.6% 0.125 141.4)
-
Step 950
950
#043000
oklch(26.9% 0.089 141.3)
#66C559 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) | #CAB54F | 0.122 |
| Deuteranopia (no green cones) | #BDAD61 | 0.121 |
| Tritanopia (no blue cones) | #5CBFAD | 0.113 |
| Achromatopsia (no color) | #B0B0B0 | 0.172 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66C559
#66C559
oklch(74.1% 0.172 141.3)
- #DC83EC
#DC83EC
oklch(74.2% 0.172 321.3)
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 #66C559, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Apple #6ECB3C ΔE 0.033
- Turtle Green #75B84F ΔE 0.035
- Soft Green #6FC276 ΔE 0.039
- Dark Mint #48C072 ΔE 0.039
- Algae Green #21C36F ΔE 0.043
- Dark Lime Green #7EBD01 ΔE 0.046
- Seaweed #18D17B ΔE 0.047
- Apple Green #76CD26 ΔE 0.048
Use #66C559 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.