#178AA5
Closest named color: Teal Blue (#01889F). oklch(58.7% 0.101 219.1), rgb(23, 138, 165).
Aa
Black text reads best on this color (5.21:1).
About this color
#178AA5 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 59%, its chroma 0.101 and its hue 219°. Its hue sits on the cool side of the wheel. The nearest named color is Teal Blue (#01889F), ΔE 0.012 away. Black text reads best on it, at 5.21:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.101) |
| Temperature | cool |
| Nearest name | Teal Blue (#01889F) |
| Black text | 5.21:1 |
| White text | 4.02:1 |
Values
| HEX | #178AA5 |
| RGB | rgb(23, 138, 165) |
| HSL | hsl(191, 76%, 37%) |
| OKLCH | oklch(58.7% 0.101 219.1) |
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 #178AA5 | 4.02:1 | AA large text | Lc -72.6 | Content text, not long reading |
| Black text on #178AA5 | 5.21:1 | AA | Lc 37.0 | Non-text elements, placeholder text |
| #178AA5 text on white | 4.02:1 | AA large text | Lc 67.1 | Content text, not long reading |
| #178AA5 text on black | 5.21:1 | AA | Lc -34.6 | 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
#F1F6F8
oklch(97% 0.006 223.5)
-
Step 100
100
#E1ECF0
oklch(93.6% 0.013 221.4)
-
Step 200
200
#C8DEE5
oklch(88.6% 0.025 218.8)
-
Step 300
300
#A1C8D5
oklch(80.9% 0.045 220.1)
-
Step 400
400
#6AACC0
oklch(70.8% 0.073 219.2)
-
Step 500
500
#3A97B0
oklch(63.2% 0.094 218.9)
-
Step 600
600 (this color)
#178AA5
oklch(58.7% 0.101 219.1)
-
Step 700
700
#006C83
oklch(49.1% 0.089 219.3)
-
Step 800
800
#00586C
oklch(42.6% 0.078 220.2)
-
Step 900
900
#104957
oklch(37.7% 0.061 218.3)
-
Step 950
950
#0D2B33
oklch(27.1% 0.038 218.3)
#178AA5 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) | #7986A6 | 0.085 |
| Deuteranopia (no green cones) | #6779A5 | 0.076 |
| Tritanopia (no blue cones) | #009393 | 0.045 |
| Achromatopsia (no color) | #7F7F7F | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178AA5
#178AA5
oklch(58.7% 0.101 219.1)
- #AF664E
#AF664E
oklch(58.7% 0.101 38.9)
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 #178AA5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Teal Blue #01889F ΔE 0.012
- Blue NCS #118AB2 ΔE 0.020
- Teal Green #0A9396 ΔE 0.041
- Dark Cyan #008B8B ΔE 0.043
- Cerulean #457B9D ΔE 0.046
- Steel Blue #4682B4 ΔE 0.046
- Off Blue #5684AE ΔE 0.049
- Cool Blue #4984B8 ΔE 0.050
Use #178AA5 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.