#178A21
Closest named color: Forest Green (#228B22). oklch(55.3% 0.171 143.7), rgb(23, 138, 33).
Aa
Black text reads best on this color (4.69:1).
About this color
#178A21 is a medium-dark, vivid green. In OKLCH its lightness is 55%, its chroma 0.171 and its hue 144°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Forest Green (#228B22), ΔE 0.006 away. Black text reads best on it, at 4.69:1.
| Hue family | Greens |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.171) |
| Temperature | in between |
| Nearest name | Forest Green (#228B22) |
| Black text | 4.69:1 |
| White text | 4.47:1 |
Values
| HEX | #178A21 |
| RGB | rgb(23, 138, 33) |
| HSL | hsl(125, 71%, 32%) |
| OKLCH | oklch(55.3% 0.171 143.7) |
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 #178A21 | 4.47:1 | AA large text | Lc -76.0 | Fine for body text |
| Black text on #178A21 | 4.69:1 | AA | Lc 33.6 | Non-text elements, placeholder text |
| #178A21 text on white | 4.47:1 | AA large text | Lc 70.5 | Content text, not long reading |
| #178A21 text on black | 4.69:1 | AA | Lc -31.2 | 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
#F1F7F1
oklch(97% 0.01 145.5)
-
Step 100
100
#E1EEE1
oklch(93.6% 0.022 145.4)
-
Step 200
200
#C9E1C8
oklch(88.5% 0.042 144.1)
-
Step 300
300
#A3CEA1
oklch(80.9% 0.077 143.7)
-
Step 400
400
#6FB46D
oklch(70.6% 0.123 143.5)
-
Step 500
500
#43A145
oklch(63.2% 0.157 143.8)
-
Step 600
600 (this color)
#178A21
oklch(55.3% 0.171 143.7)
-
Step 700
700
#047614
oklch(49.2% 0.159 143.7)
-
Step 800
800
#0D6014
oklch(42.7% 0.132 143.7)
-
Step 900
900
#174F19
oklch(37.8% 0.103 143.7)
-
Step 950
950
#0F2E10
oklch(26.9% 0.064 144.1)
#178A21 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) | #8D7C0C | 0.124 |
| Deuteranopia (no green cones) | #81742C | 0.124 |
| Tritanopia (no blue cones) | #008676 | 0.109 |
| Achromatopsia (no color) | #777777 | 0.172 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178A21
#178A21
oklch(55.3% 0.171 143.7)
- #A047AA
#A047AA
oklch(55.2% 0.172 323.5)
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 #178A21, closest first.
No curated palette has a color within ΔE 0.04 of #178A21.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Forest Green #228B22 ΔE 0.006
- Emerald Green #028F1E ΔE 0.016
- Kelley Green #009337 ΔE 0.028
- Dark Grass Green #388004 ΔE 0.030
- Irish Green #019529 ΔE 0.032
- Green #008000 ΔE 0.034
- Tree Green #2A7E19 ΔE 0.035
- True Green #089404 ΔE 0.035
Use #178A21 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.