#0171DB
Closest named color: Cerulean Blue (#056EEE). oklch(55.7% 0.183 255), rgb(1, 113, 219).
Aa
White text reads best on this color (4.78:1).
About this color
#0171DB is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.183 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean Blue (#056EEE), ΔE 0.031 away. White text reads best on it, at 4.78:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.183) |
| Temperature | cool |
| Nearest name | Cerulean Blue (#056EEE) |
| Black text | 4.38:1 |
| White text | 4.78:1 |
Values
| HEX | #0171DB |
| RGB | rgb(1, 113, 219) |
| HSL | hsl(209, 99%, 43%) |
| OKLCH | oklch(55.7% 0.183 255) |
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 #0171DB | 4.78:1 | AA | Lc -77.9 | Fine for body text |
| Black text on #0171DB | 4.38:1 | AA large text | Lc 31.7 | Non-text elements, placeholder text |
| #0171DB text on white | 4.78:1 | AA | Lc 72.4 | Content text, not long reading |
| #0171DB text on black | 4.38:1 | AA large text | Lc -29.3 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFA
oklch(93.6% 0.024 256.1)
-
Step 200
200
#C5DBF8
oklch(88.4% 0.047 255.4)
-
Step 300
300
#9DC4F6
oklch(81% 0.083 254.9)
-
Step 400
400
#65A3F1
oklch(70.7% 0.132 254.9)
-
Step 500
500
#3689EC
oklch(63% 0.169 255.1)
-
Step 600
600 (this color)
#0171DB
oklch(55.7% 0.183 255)
-
Step 700
700
#005EB9
oklch(49% 0.162 255.1)
-
Step 800
800
#004D99
oklch(42.7% 0.14 255)
-
Step 900
900
#0F417A
oklch(37.7% 0.11 255)
-
Step 950
950
#0B2747
oklch(27.1% 0.068 254.1)
#0171DB 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) | #2F7CDF | 0.038 |
| Deuteranopia (no green cones) | #006AD9 | 0.018 |
| Tritanopia (no blue cones) | #008B9B | 0.137 |
| Achromatopsia (no color) | #727272 | 0.183 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0171DB
#0171DB
oklch(55.7% 0.183 255)
- #9B6800
#9B6800
oklch(55.7% 0.117 75.3)
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 #0171DB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean Blue #056EEE ΔE 0.031
- Royal Blue #4169E1 ΔE 0.037
- Windows Blue #3778BF ΔE 0.055
- Azul #1D5DEC ΔE 0.055
- Neon Blue #4361EE ΔE 0.057
- Clear Blue #247AFD ΔE 0.058
- Bright Blue #0165FC ΔE 0.059
- Mid Blue #276AB3 ΔE 0.062
Use #0171DB 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.