#178ABA
Closest named color: Blue NCS (#118AB2). oklch(59.7% 0.118 233.2), rgb(23, 138, 186).
Aa
Black text reads best on this color (5.38:1).
About this color
#178ABA is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.118 and its hue 233°. Its hue sits on the cool side of the wheel. The nearest named color is Blue NCS (#118AB2), ΔE 0.013 away. Black text reads best on it, at 5.38:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.118) |
| Temperature | cool |
| Nearest name | Blue NCS (#118AB2) |
| Black text | 5.38:1 |
| White text | 3.90:1 |
Values
| HEX | #178ABA |
| RGB | rgb(23, 138, 186) |
| HSL | hsl(198, 78%, 41%) |
| OKLCH | oklch(59.7% 0.118 233.2) |
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 #178ABA | 3.90:1 | AA large text | Lc -71.5 | Content text, not long reading |
| Black text on #178ABA | 5.38:1 | AA | Lc 38.1 | Non-text elements, placeholder text |
| #178ABA text on white | 3.90:1 | AA large text | Lc 66.0 | Content text, not long reading |
| #178ABA text on black | 5.38:1 | AA | Lc -35.7 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E0ECF3
oklch(93.6% 0.016 233)
-
Step 200
200
#C5DDEB
oklch(88.4% 0.032 233.3)
-
Step 300
300
#9CC8E0
oklch(81% 0.057 232.2)
-
Step 400
400
#61AAD1
oklch(70.6% 0.093 233.5)
-
Step 500
500 (this color)
#178ABA
oklch(59.7% 0.118 233.2)
-
Step 600
600
#007DAB
oklch(55.5% 0.115 233.2)
-
Step 700
700
#006991
oklch(49% 0.102 233.6)
-
Step 800
800
#005677
oklch(42.6% 0.088 233.1)
-
Step 900
900
#024864
oklch(37.8% 0.077 233.1)
-
Step 950
950
#072A3A
oklch(26.9% 0.049 232.7)
#178ABA 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) | #7289BC | 0.074 |
| Deuteranopia (no green cones) | #5D7BB9 | 0.061 |
| Tritanopia (no blue cones) | #00979A | 0.072 |
| Achromatopsia (no color) | #818181 | 0.118 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178ABA
#178ABA
oklch(59.7% 0.118 233.2)
- #B56934
#B56934
oklch(59.6% 0.118 53.1)
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 #178ABA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blue NCS #118AB2 ΔE 0.013
- Water Blue #0E87CC ΔE 0.031
- Cool Blue #4984B8 ΔE 0.031
- Steel Blue #4682B4 ΔE 0.031
- Teal Blue #01889F ΔE 0.043
- Off Blue #5684AE ΔE 0.043
- Nice Blue #107AB0 ΔE 0.047
- Dusty Blue #5A86AD ΔE 0.047
Use #178ABA 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.