#178EC5
Closest named color: Water Blue (#0E87CC). oklch(61.2% 0.126 236.1), rgb(23, 142, 197).
Aa
Black text reads best on this color (5.71:1).
About this color
#178EC5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 61%, its chroma 0.126 and its hue 236°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.025 away. Black text reads best on it, at 5.71:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.71:1 |
| White text | 3.67:1 |
Values
| HEX | #178EC5 |
| RGB | rgb(23, 142, 197) |
| HSL | hsl(199, 79%, 43%) |
| OKLCH | oklch(61.2% 0.126 236.1) |
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 #178EC5 | 3.67:1 | AA large text | Lc -69.3 | Content text, not long reading |
| Black text on #178EC5 | 5.71:1 | AA | Lc 40.2 | Non-text elements, placeholder text |
| #178EC5 text on white | 3.67:1 | AA large text | Lc 63.8 | Content text, not long reading |
| #178EC5 text on black | 5.71:1 | AA | Lc -37.8 | 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
#F0F6FA
oklch(97% 0.008 236.6)
-
Step 100
100
#DFECF4
oklch(93.6% 0.018 234.5)
-
Step 200
200
#C5DDED
oklch(88.5% 0.034 237)
-
Step 300
300
#9BC8E4
oklch(81% 0.062 235.9)
-
Step 400
400
#5FAAD6
oklch(70.7% 0.099 236.2)
-
Step 500
500 (this color)
#178EC5
oklch(61.2% 0.126 236.1)
-
Step 600
600
#007CAF
oklch(55.5% 0.12 236.1)
-
Step 700
700
#006994
oklch(49.2% 0.105 235.5)
-
Step 800
800
#00567A
oklch(42.8% 0.091 235.4)
-
Step 900
900
#004767
oklch(37.7% 0.082 236.6)
-
Step 950
950
#062A3C
oklch(27% 0.052 235.4)
#178EC5 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) | #738EC7 | 0.073 |
| Deuteranopia (no green cones) | #5D7FC4 | 0.059 |
| Tritanopia (no blue cones) | #009CA1 | 0.079 |
| Achromatopsia (no color) | #858585 | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178EC5
#178EC5
oklch(61.2% 0.126 236.1)
- #BC6D2D
#BC6D2D
oklch(61.2% 0.126 56)
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 #178EC5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.025
- Blue NCS #118AB2 ΔE 0.030
- Cool Blue #4984B8 ΔE 0.037
- Steel Blue #4682B4 ΔE 0.041
- Off Blue #5684AE ΔE 0.051
- Dusty Blue #5A86AD ΔE 0.053
- Faded Blue #658CBB ΔE 0.056
- Dark Sky Blue #448EE4 ΔE 0.056
Use #178EC5 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.