#178D9D
Closest named color: Teal Blue (#01889F). oklch(59.1% 0.097 209.5), rgb(23, 141, 157).
Aa
Black text reads best on this color (5.33:1).
About this color
#178D9D is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 59%, its chroma 0.097 and its hue 209°. Its hue sits on the cool side of the wheel. The nearest named color is Teal Blue (#01889F), ΔE 0.018 away. Black text reads best on it, at 5.33:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Teal Blue (#01889F) |
| Black text | 5.33:1 |
| White text | 3.93:1 |
Values
| HEX | #178D9D |
| RGB | rgb(23, 141, 157) |
| HSL | hsl(187, 74%, 35%) |
| OKLCH | oklch(59.1% 0.097 209.5) |
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 #178D9D | 3.93:1 | AA large text | Lc -71.8 | Content text, not long reading |
| Black text on #178D9D | 5.33:1 | AA | Lc 37.8 | Non-text elements, placeholder text |
| #178D9D text on white | 3.93:1 | AA large text | Lc 66.3 | Content text, not long reading |
| #178D9D text on black | 5.33:1 | AA | Lc -35.4 | 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
#E1ECEE
oklch(93.5% 0.012 209.8)
-
Step 200
200
#C8DEE2
oklch(88.5% 0.024 209.8)
-
Step 300
300
#A1C9D0
oklch(80.9% 0.043 209.4)
-
Step 400
400
#6AADB8
oklch(70.7% 0.07 209)
-
Step 500
500
#3998A7
oklch(63% 0.09 209.7)
-
Step 600
600 (this color)
#178D9D
oklch(59.1% 0.097 209.5)
-
Step 700
700
#006D7B
oklch(49% 0.085 210.2)
-
Step 800
800
#005A65
oklch(42.8% 0.074 209.1)
-
Step 900
900
#104A52
oklch(37.7% 0.058 208.6)
-
Step 950
950
#0C2B30
oklch(26.9% 0.037 209.8)
#178D9D 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) | #7F879E | 0.092 |
| Deuteranopia (no green cones) | #6E7B9D | 0.084 |
| Tritanopia (no blue cones) | #009492 | 0.031 |
| Achromatopsia (no color) | #808080 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178D9D
#178D9D
oklch(59.1% 0.097 209.5)
- #B0665B
#B0665B
oklch(59.1% 0.098 29.3)
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 #178D9D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Teal Blue #01889F ΔE 0.018
- Teal Green #0A9396 ΔE 0.024
- Dark Cyan #008B8B ΔE 0.029
- Blue NCS #118AB2 ΔE 0.037
- Dusty Teal #4C9085 ΔE 0.049
- Sea #3C9992 ΔE 0.050
- Teal #008080 ΔE 0.054
- Blue Green #0F9B8E ΔE 0.054
Use #178D9D 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.