#178B70
Closest named color: Viridian (#1E9167). oklch(57% 0.105 171.9), rgb(23, 139, 112).
Aa
Black text reads best on this color (4.96:1).
About this color
#178B70 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 57%, its chroma 0.105 and its hue 172°. Its hue sits on the cool side of the wheel. The nearest named color is Viridian (#1E9167), ΔE 0.026 away. Black text reads best on it, at 4.96:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.105) |
| Temperature | cool |
| Nearest name | Viridian (#1E9167) |
| Black text | 4.96:1 |
| White text | 4.23:1 |
Values
| HEX | #178B70 |
| RGB | rgb(23, 139, 112) |
| HSL | hsl(166, 72%, 32%) |
| OKLCH | oklch(57% 0.105 171.9) |
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 #178B70 | 4.23:1 | AA large text | Lc -74.3 | Content text, not long reading |
| Black text on #178B70 | 4.96:1 | AA | Lc 35.3 | Non-text elements, placeholder text |
| #178B70 text on white | 4.23:1 | AA large text | Lc 68.8 | Content text, not long reading |
| #178B70 text on black | 4.96:1 | AA | Lc -32.9 | 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
#F1F7F5
oklch(97.1% 0.007 174.4)
-
Step 100
100
#E1EDE9
oklch(93.6% 0.014 174.2)
-
Step 200
200
#C9DFD7
oklch(88.5% 0.026 171.9)
-
Step 300
300
#A2CBBD
oklch(80.9% 0.048 172.2)
-
Step 400
400
#6DB09B
oklch(70.6% 0.076 172.1)
-
Step 500
500
#3F9C83
oklch(63% 0.096 172.5)
-
Step 600
600 (this color)
#178B70
oklch(57% 0.105 171.9)
-
Step 700
700
#00725A
oklch(49.2% 0.096 171.5)
-
Step 800
800
#065D4A
oklch(42.7% 0.081 172.2)
-
Step 900
900
#144C3E
oklch(37.6% 0.062 172.8)
-
Step 950
950
#0E2D24
oklch(27.1% 0.041 171.3)
#178B70 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) | #86816F | 0.108 |
| Deuteranopia (no green cones) | #787772 | 0.103 |
| Tritanopia (no blue cones) | #008C83 | 0.028 |
| Achromatopsia (no color) | #7B7B7B | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178B70
#178B70
oklch(57% 0.105 171.9)
- #A65C7E
#A65C7E
oklch(57.1% 0.105 352)
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 #178B70, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Viridian #1E9167 ΔE 0.026
- Sea Green #2E8B57 ΔE 0.036
- Dark Cyan #008B8B ΔE 0.041
- Teal #008080 ΔE 0.049
- Ocean Green #3D9973 ΔE 0.050
- Dusty Teal #4C9085 ΔE 0.051
- Dark Sage #598556 ΔE 0.051
- Blue Green #0F9B8E ΔE 0.056
Use #178B70 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.