#0178C4
Closest named color: Windows Blue (#3778BF). oklch(55.7% 0.147 247.2), rgb(1, 120, 196).
Aa
White text reads best on this color (4.68:1).
About this color
#0178C4 is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.147 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.024 away. White text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.147) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.48:1 |
| White text | 4.68:1 |
Values
| HEX | #0178C4 |
| RGB | rgb(1, 120, 196) |
| HSL | hsl(203, 99%, 39%) |
| OKLCH | oklch(55.7% 0.147 247.2) |
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 #0178C4 | 4.68:1 | AA | Lc -77.3 | Fine for body text |
| Black text on #0178C4 | 4.48:1 | AA large text | Lc 32.2 | Non-text elements, placeholder text |
| #0178C4 text on white | 4.68:1 | AA | Lc 71.8 | Content text, not long reading |
| #0178C4 text on black | 4.48:1 | AA large text | Lc -29.8 | Dividers and decoration only |
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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E0EBF6
oklch(93.5% 0.019 248)
-
Step 200
200
#C7DCF1
oklch(88.5% 0.037 248.2)
-
Step 300
300
#9FC5EA
oklch(80.9% 0.066 248)
-
Step 400
400
#68A6DF
oklch(70.6% 0.106 247.6)
-
Step 500
500
#398FD6
oklch(63.1% 0.135 247.1)
-
Step 600
600 (this color)
#0178C4
oklch(55.7% 0.147 247.2)
-
Step 700
700
#0064A5
oklch(49% 0.13 247.2)
-
Step 800
800
#005289
oklch(42.7% 0.113 247.3)
-
Step 900
900
#10446D
oklch(37.6% 0.088 247.3)
-
Step 950
950
#0C2840
oklch(26.9% 0.056 247.6)
#0178C4 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) | #527CC7 | 0.052 |
| Deuteranopia (no green cones) | #356DC3 | 0.034 |
| Tritanopia (no blue cones) | #008B94 | 0.105 |
| Achromatopsia (no color) | #747474 | 0.147 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0178C4
#0178C4
oklch(55.7% 0.147 247.2)
- #A36300
#A36300
oklch(55.8% 0.123 66.9)
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 #0178C4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.024
- Nice Blue #107AB0 ΔE 0.033
- Mid Blue #276AB3 ΔE 0.042
- Water Blue #0E87CC ΔE 0.043
- Flat Blue #3C73A8 ΔE 0.048
- French Blue #436BAD ΔE 0.052
- Steel Blue #4682B4 ΔE 0.057
- Muted Blue #3B719F ΔE 0.060
Use #0178C4 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.