#178C5B
Closest named color: Sea Green (#2E8B57). oklch(56.7% 0.124 159), rgb(23, 140, 91).
Aa
Black text reads best on this color (4.93:1).
About this color
#178C5B is a medium-dark, moderately saturated green. In OKLCH its lightness is 57%, its chroma 0.124 and its hue 159°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Sea Green (#2E8B57), ΔE 0.010 away. Black text reads best on it, at 4.93:1.
| Hue family | Greens |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.124) |
| Temperature | in between |
| Nearest name | Sea Green (#2E8B57) |
| Black text | 4.93:1 |
| White text | 4.25:1 |
Values
| HEX | #178C5B |
| RGB | rgb(23, 140, 91) |
| HSL | hsl(155, 72%, 32%) |
| OKLCH | oklch(56.7% 0.124 159) |
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 #178C5B | 4.25:1 | AA large text | Lc -74.4 | Content text, not long reading |
| Black text on #178C5B | 4.93:1 | AA | Lc 35.2 | Non-text elements, placeholder text |
| #178C5B text on white | 4.25:1 | AA large text | Lc 68.9 | Content text, not long reading |
| #178C5B text on black | 4.93:1 | AA | Lc -32.8 | 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
#F1F7F4
oklch(97.1% 0.007 164.9)
-
Step 100
100
#E1EDE6
oklch(93.5% 0.016 160.6)
-
Step 200
200
#C9E0D2
oklch(88.6% 0.031 159)
-
Step 300
300
#A3CCB4
oklch(80.9% 0.055 159.2)
-
Step 400
400
#6EB28C
oklch(70.7% 0.089 158.6)
-
Step 500
500
#409E70
oklch(63% 0.114 159.1)
-
Step 600
600 (this color)
#178C5B
oklch(56.7% 0.124 159)
-
Step 700
700
#007348
oklch(49% 0.113 158.9)
-
Step 800
800
#075E3B
oklch(42.6% 0.095 159)
-
Step 900
900
#154D33
oklch(37.6% 0.073 159.2)
-
Step 950
950
#0E2D1E
oklch(26.9% 0.047 159.7)
#178C5B 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) | #8A8058 | 0.115 |
| Deuteranopia (no green cones) | #7D775E | 0.112 |
| Tritanopia (no blue cones) | #008B7F | 0.054 |
| Achromatopsia (no color) | #7B7B7B | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178C5B
#178C5B
oklch(56.7% 0.124 159)
- #A5578F
#A5578F
oklch(56.8% 0.124 338.8)
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 #178C5B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sea Green #2E8B57 ΔE 0.010
- Viridian #1E9167 ΔE 0.020
- Jungle Green #048243 ΔE 0.040
- Light Forest Green #4F9153 ΔE 0.042
- Fern Green #548D44 ΔE 0.046
- Dark Sage #598556 ΔE 0.048
- Ocean Green #3D9973 ΔE 0.054
- Kelley Green #009337 ΔE 0.055
Use #178C5B 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.