#178FB1
Closest named color: Blue NCS (#118AB2). oklch(60.5% 0.108 223.5), rgb(23, 143, 177).
Aa
Black text reads best on this color (5.60:1).
About this color
#178FB1 is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 60%, its chroma 0.108 and its hue 223°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.016 away. Black text reads best on it, at 5.60:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 5.60:1 |
| White text | 3.74:1 |
Values
| HEX | #178FB1 |
| RGB | rgb(23, 143, 177) |
| HSL | hsl(193, 77%, 39%) |
| OKLCH | oklch(60.5% 0.108 223.5) |
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 #178FB1 | 3.74:1 | AA large text | Lc -70.1 | Content text, not long reading |
| Black text on #178FB1 | 5.60:1 | AA | Lc 39.5 | Non-text elements, placeholder text |
| #178FB1 text on white | 3.74:1 | AA large text | Lc 64.6 | Content text, not long reading |
| #178FB1 text on black | 5.60:1 | AA | Lc -37.1 | 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
#C5DEE8
oklch(88.5% 0.03 223.8)
-
Step 300
300
#9CC9DA
oklch(81% 0.053 223)
-
Step 400
400
#61ACC7
oklch(70.6% 0.084 223.5)
-
Step 500
500 (this color)
#178FB1
oklch(60.5% 0.108 223.5)
-
Step 600
600
#0080A0
oklch(55.7% 0.104 223.4)
-
Step 700
700
#006B87
oklch(49% 0.092 224)
-
Step 800
800
#00586F
oklch(42.7% 0.08 223.4)
-
Step 900
900
#00495D
oklch(37.7% 0.071 223.8)
-
Step 950
950
#072B36
oklch(27% 0.044 222.7)
#178FB1 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) | #7C8CB3 | 0.085 |
| Deuteranopia (no green cones) | #687EB1 | 0.074 |
| Tritanopia (no blue cones) | #00999A | 0.053 |
| Achromatopsia (no color) | #848484 | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178FB1
#178FB1
oklch(60.5% 0.108 223.5)
- #B76B4A
#B76B4A
oklch(60.5% 0.108 43.8)
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 #178FB1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.016
- Teal Blue #01889F ΔE 0.032
- Cool Blue #4984B8 ΔE 0.044
- Steel Blue #4682B4 ΔE 0.044
- Off Blue #5684AE ΔE 0.047
- Teal Green #0A9396 ΔE 0.048
- Dusty Blue #5A86AD ΔE 0.048
- Water Blue #0E87CC ΔE 0.053
Use #178FB1 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.