#178DC4
Closest named color: Water Blue (#0E87CC). oklch(60.9% 0.126 236.3), rgb(23, 141, 196).
Aa
Black text reads best on this color (5.64:1).
About this color
#178DC4 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 0.024 away. Black text reads best on it, at 5.64:1.
| Hue family | Blues |
| Lightness | medium-dark (61%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.64:1 |
| White text | 3.72:1 |
Values
| HEX | #178DC4 |
| RGB | rgb(23, 141, 196) |
| HSL | hsl(199, 79%, 43%) |
| OKLCH | oklch(60.9% 0.126 236.3) |
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 #178DC4 | 3.72:1 | AA large text | Lc -69.8 | Content text, not long reading |
| Black text on #178DC4 | 5.64:1 | AA | Lc 39.8 | Non-text elements, placeholder text |
| #178DC4 text on white | 3.72:1 | AA large text | Lc 64.3 | Content text, not long reading |
| #178DC4 text on black | 5.64:1 | AA | Lc -37.4 | 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
#9BC7E4
oklch(80.8% 0.062 237.4)
-
Step 400
400
#5FAAD6
oklch(70.7% 0.099 236.2)
-
Step 500
500 (this color)
#178DC4
oklch(60.9% 0.126 236.3)
-
Step 600
600
#007CB0
oklch(55.5% 0.121 236.7)
-
Step 700
700
#006894
oklch(49% 0.106 236.4)
-
Step 800
800
#00557A
oklch(42.5% 0.092 236.4)
-
Step 900
900
#004767
oklch(37.7% 0.082 236.6)
-
Step 950
950
#062A3C
oklch(27% 0.052 235.4)
#178DC4 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) | #728DC6 | 0.072 |
| Deuteranopia (no green cones) | #5C7EC3 | 0.059 |
| Tritanopia (no blue cones) | #009BA0 | 0.079 |
| Achromatopsia (no color) | #848484 | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #178DC4
#178DC4
oklch(60.9% 0.126 236.3)
- #BB6D2C
#BB6D2C
oklch(61% 0.126 56.6)
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 #178DC4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.024
- Blue NCS #118AB2 ΔE 0.028
- Cool Blue #4984B8 ΔE 0.035
- Steel Blue #4682B4 ΔE 0.039
- Off Blue #5684AE ΔE 0.050
- Dusty Blue #5A86AD ΔE 0.052
- Faded Blue #658CBB ΔE 0.056
- Dark Sky Blue #448EE4 ΔE 0.057
Use #178DC4 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.