#178DAD
Closest named color: Blue NCS (#118AB2). oklch(59.8% 0.106 222.4), rgb(23, 141, 173).
Aa
Black text reads best on this color (5.44:1).
About this color
#178DAD is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 60%, its chroma 0.106 and its hue 222°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.014 away. Black text reads best on it, at 5.44:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.106) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 5.44:1 |
| White text | 3.85:1 |
Values
| HEX | #178DAD |
| RGB | rgb(23, 141, 173) |
| HSL | hsl(193, 77%, 38%) |
| OKLCH | oklch(59.8% 0.106 222.4) |
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 #178DAD | 3.85:1 | AA large text | Lc -71.0 | Content text, not long reading |
| Black text on #178DAD | 5.44:1 | AA | Lc 38.5 | Non-text elements, placeholder text |
| #178DAD text on white | 3.85:1 | AA large text | Lc 65.5 | Content text, not long reading |
| #178DAD text on black | 5.44:1 | AA | Lc -36.1 | 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 500.
-
Step 50
50
#F1F7F9
oklch(97.2% 0.007 219.6)
-
Step 100
100
#E0ECF1
oklch(93.6% 0.015 224.5)
-
Step 200
200
#C6DEE7
oklch(88.6% 0.028 222.3)
-
Step 300
300
#9DC9D9
oklch(81% 0.052 222.1)
-
Step 400
400
#62ACC6
oklch(70.6% 0.083 222.9)
-
Step 500
500 (this color)
#178DAD
oklch(59.8% 0.106 222.4)
-
Step 600
600
#00809F
oklch(55.6% 0.103 222.6)
-
Step 700
700
#006B86
oklch(49% 0.091 223.1)
-
Step 800
800
#00586E
oklch(42.7% 0.079 222.3)
-
Step 900
900
#02495C
oklch(37.6% 0.069 222.9)
-
Step 950
950
#072B36
oklch(27% 0.044 222.7)
#178DAD 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) | #7A89AF | 0.084 |
| Deuteranopia (no green cones) | #687CAD | 0.075 |
| Tritanopia (no blue cones) | #009797 | 0.052 |
| Achromatopsia (no color) | #828282 | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178DAD
#178DAD
oklch(59.8% 0.106 222.4)
- #B4694B
#B4694B
oklch(59.8% 0.106 42.3)
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 #178DAD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.014
- Teal Blue #01889F ΔE 0.025
- Steel Blue #4682B4 ΔE 0.043
- Cool Blue #4984B8 ΔE 0.045
- Teal Green #0A9396 ΔE 0.045
- Off Blue #5684AE ΔE 0.047
- Dusty Blue #5A86AD ΔE 0.048
- Cerulean #457B9D ΔE 0.053
Use #178DAD 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.