#178AAF
Closest named color: Blue NCS (#118AB2). oklch(59.2% 0.108 226.4), rgb(23, 138, 175).
Aa
Black text reads best on this color (5.29:1).
About this color
#178AAF is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 59%, its chroma 0.108 and its hue 226°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.005 away. Black text reads best on it, at 5.29:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 5.29:1 |
| White text | 3.96:1 |
Values
| HEX | #178AAF |
| RGB | rgb(23, 138, 175) |
| HSL | hsl(195, 77%, 39%) |
| OKLCH | oklch(59.2% 0.108 226.4) |
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 #178AAF | 3.96:1 | AA large text | Lc -72.1 | Content text, not long reading |
| Black text on #178AAF | 5.29:1 | AA | Lc 37.5 | Non-text elements, placeholder text |
| #178AAF text on white | 3.96:1 | AA large text | Lc 66.6 | Content text, not long reading |
| #178AAF text on black | 5.29:1 | AA | Lc -35.1 | 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 600.
-
Step 50
50
#F1F6F9
oklch(97% 0.007 233.6)
-
Step 100
100
#E1ECF1
oklch(93.6% 0.014 226.6)
-
Step 200
200
#C7DDE7
oklch(88.4% 0.027 226.8)
-
Step 300
300
#A0C8D9
oklch(81% 0.049 225.7)
-
Step 400
400
#69ABC6
oklch(70.7% 0.078 226.1)
-
Step 500
500
#3995B8
oklch(63% 0.1 227)
-
Step 600
600 (this color)
#178AAF
oklch(59.2% 0.108 226.4)
-
Step 700
700
#006B8A
oklch(49.2% 0.095 226.5)
-
Step 800
800
#005771
oklch(42.6% 0.082 226.6)
-
Step 900
900
#0F485C
oklch(37.6% 0.065 226.7)
-
Step 950
950
#0C2A36
oklch(26.9% 0.042 227.8)
#178AAF 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) | #7687B1 | 0.080 |
| Deuteranopia (no green cones) | #637AAF | 0.069 |
| Tritanopia (no blue cones) | #009596 | 0.058 |
| Achromatopsia (no color) | #808080 | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178AAF
#178AAF
oklch(59.2% 0.108 226.4)
- #B26843
#B26843
oklch(59.2% 0.108 46.5)
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 #178AAF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.005
- Teal Blue #01889F ΔE 0.026
- Steel Blue #4682B4 ΔE 0.036
- Cool Blue #4984B8 ΔE 0.038
- Off Blue #5684AE ΔE 0.043
- Dusty Blue #5A86AD ΔE 0.046
- Cerulean #457B9D ΔE 0.048
- Water Blue #0E87CC ΔE 0.048
Use #178AAF 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.