#0178DD
Closest named color: Cerulean Blue (#056EEE). oklch(57.4% 0.178 253.2), rgb(1, 120, 221).
Aa
Black text reads best on this color (4.73:1).
About this color
#0178DD is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.178 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.038 away. Black text reads best on it, at 4.73:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.178) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.73:1 |
| White text | 4.43:1 |
Values
| HEX | #0178DD |
| RGB | rgb(1, 120, 221) |
| HSL | hsl(208, 99%, 44%) |
| OKLCH | oklch(57.4% 0.178 253.2) |
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 #0178DD | 4.43:1 | AA large text | Lc -75.5 | Fine for body text |
| Black text on #0178DD | 4.73:1 | AA | Lc 34.1 | Non-text elements, placeholder text |
| #0178DD text on white | 4.43:1 | AA large text | Lc 70.0 | Content text, not long reading |
| #0178DD text on black | 4.73:1 | AA | Lc -31.7 | 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 600.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#DFEBF9
oklch(93.5% 0.023 252.2)
-
Step 200
200
#C5DCF7
oklch(88.6% 0.045 252.5)
-
Step 300
300
#9CC4F4
oklch(80.9% 0.081 253.3)
-
Step 400
400
#64A4EE
oklch(70.7% 0.128 253.1)
-
Step 500
500
#338BE9
oklch(63.2% 0.164 253.2)
-
Step 600
600 (this color)
#0178DD
oklch(57.4% 0.178 253.2)
-
Step 700
700
#0060B4
oklch(49.1% 0.153 253.4)
-
Step 800
800
#004F95
oklch(42.8% 0.133 253.1)
-
Step 900
900
#0C4278
oklch(37.7% 0.106 253.1)
-
Step 950
950
#0A2746
oklch(27% 0.067 252.9)
#0178DD 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) | #3F81E1 | 0.041 |
| Deuteranopia (no green cones) | #0070DB | 0.021 |
| Tritanopia (no blue cones) | #0091A0 | 0.131 |
| Achromatopsia (no color) | #787878 | 0.178 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0178DD
#0178DD
oklch(57.4% 0.178 253.2)
- #A36B00
#A36B00
oklch(57.3% 0.122 73.2)
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 #0178DD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.038
- Royal Blue #4169E1 ΔE 0.046
- Windows Blue #3778BF ΔE 0.050
- Clear Blue #247AFD ΔE 0.051
- Water Blue #0E87CC ΔE 0.053
- Neon Blue #4361EE ΔE 0.067
- Bright Blue #0165FC ΔE 0.068
- Mid Blue #276AB3 ΔE 0.070
Use #0178DD 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.