#178A91
Closest named color: Dark Cyan (#008B8B). oklch(57.8% 0.094 201.5), rgb(23, 138, 145).
Aa
Black text reads best on this color (5.08:1).
About this color
#178A91 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 58%, its chroma 0.094 and its hue 201°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Cyan (#008B8B), ΔE 0.012 away. Black text reads best on it, at 5.08:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.094) |
| Temperature | cool |
| Nearest name | Dark Cyan (#008B8B) |
| Black text | 5.08:1 |
| White text | 4.13:1 |
Values
| HEX | #178A91 |
| RGB | rgb(23, 138, 145) |
| HSL | hsl(183, 73%, 33%) |
| OKLCH | oklch(57.8% 0.094 201.5) |
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 #178A91 | 4.13:1 | AA large text | Lc -73.5 | Content text, not long reading |
| Black text on #178A91 | 5.08:1 | AA | Lc 36.1 | Non-text elements, placeholder text |
| #178A91 text on white | 4.13:1 | AA large text | Lc 68.0 | Content text, not long reading |
| #178A91 text on black | 5.08:1 | AA | Lc -33.7 | 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
#F1F7F7
oklch(97.2% 0.006 197.1)
-
Step 100
100
#E1ECED
oklch(93.5% 0.012 203.5)
-
Step 200
200
#C8DEDF
oklch(88.5% 0.024 200.1)
-
Step 300
300
#A2C9CC
oklch(80.9% 0.042 202.2)
-
Step 400
400
#6CAEB2
oklch(70.8% 0.068 200.7)
-
Step 500
500
#3D999F
oklch(63.1% 0.086 201.2)
-
Step 600
600 (this color)
#178A91
oklch(57.8% 0.094 201.5)
-
Step 700
700
#006E74
oklch(49% 0.083 201.4)
-
Step 800
800
#025A5F
oklch(42.6% 0.072 201.4)
-
Step 900
900
#124A4E
oklch(37.6% 0.056 202)
-
Step 950
950
#0D2C2E
oklch(27.1% 0.036 201.1)
#178A91 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) | #7F8492 | 0.095 |
| Deuteranopia (no green cones) | #6E7891 | 0.086 |
| Tritanopia (no blue cones) | #00908C | 0.022 |
| Achromatopsia (no color) | #7D7D7D | 0.094 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178A91
#178A91
oklch(57.8% 0.094 201.5)
- #AA6261
#AA6261
oklch(57.7% 0.094 21.2)
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 #178A91, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Cyan #008B8B ΔE 0.012
- Teal Blue #01889F ΔE 0.025
- Teal Green #0A9396 ΔE 0.026
- Teal #008080 ΔE 0.037
- Dusty Teal #4C9085 ΔE 0.044
- Ocean #017B92 ΔE 0.048
- Blue NCS #118AB2 ΔE 0.052
- Sea #3C9992 ΔE 0.052
Use #178A91 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.