#178CA3
Closest named color: Teal Blue (#01889F). oklch(59.1% 0.1 215.5), rgb(23, 140, 163).
Aa
Black text reads best on this color (5.31:1).
About this color
#178CA3 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 59%, its chroma 0.100 and its hue 216°. Its hue sits on the cool side of the wheel. The nearest named color is Teal Blue (#01889F), ΔE 0.014 away. Black text reads best on it, at 5.31:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.100) |
| Temperature | cool |
| Nearest name | Teal Blue (#01889F) |
| Black text | 5.31:1 |
| White text | 3.94:1 |
Values
| HEX | #178CA3 |
| RGB | rgb(23, 140, 163) |
| HSL | hsl(190, 75%, 36%) |
| OKLCH | oklch(59.1% 0.1 215.5) |
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 #178CA3 | 3.94:1 | AA large text | Lc -71.9 | Content text, not long reading |
| Black text on #178CA3 | 5.31:1 | AA | Lc 37.7 | Non-text elements, placeholder text |
| #178CA3 text on white | 3.94:1 | AA large text | Lc 66.4 | Content text, not long reading |
| #178CA3 text on black | 5.31:1 | AA | Lc -35.2 | 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
#E1ECEF
oklch(93.6% 0.012 215.8)
-
Step 200
200
#C8DEE4
oklch(88.6% 0.025 215.9)
-
Step 300
300
#A0C9D3
oklch(81% 0.046 214.2)
-
Step 400
400
#6AACBD
oklch(70.7% 0.072 216)
-
Step 500
500
#3997AD
oklch(63% 0.092 216.2)
-
Step 600
600 (this color)
#178CA3
oklch(59.1% 0.1 215.5)
-
Step 700
700
#006D80
oklch(49.2% 0.087 215.3)
-
Step 800
800
#005969
oklch(42.7% 0.076 215.4)
-
Step 900
900
#104956
oklch(37.6% 0.06 216.8)
-
Step 950
950
#0C2B32
oklch(27% 0.038 215.2)
#178CA3 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) | #7C87A4 | 0.088 |
| Deuteranopia (no green cones) | #6A7AA3 | 0.080 |
| Tritanopia (no blue cones) | #009493 | 0.040 |
| Achromatopsia (no color) | #808080 | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178CA3
#178CA3
oklch(59.1% 0.1 215.5)
- #B16753
#B16753
oklch(59.2% 0.1 36)
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 #178CA3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Teal Blue #01889F ΔE 0.014
- Blue NCS #118AB2 ΔE 0.026
- Teal Green #0A9396 ΔE 0.034
- Dark Cyan #008B8B ΔE 0.039
- Cerulean #457B9D ΔE 0.051
- Steel Blue #4682B4 ΔE 0.052
- Off Blue #5684AE ΔE 0.053
- Dusty Blue #5A86AD ΔE 0.053
Use #178CA3 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.