#0366D4
Closest named color: Azul (#1D5DEC). oklch(52.8% 0.187 257.2), rgb(3, 102, 212).
Aa
White text reads best on this color (5.44:1).
About this color
#0366D4 is a medium-dark, vivid blue. In OKLCH its lightness is 53%, its chroma 0.187 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Azul (#1D5DEC), ΔE 0.043 away. White text reads best on it, at 5.44:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.187) |
| Temperature | cool |
| Nearest name | Azul (#1D5DEC) |
| Black text | 3.85:1 |
| White text | 5.44:1 |
Values
| HEX | #0366D4 |
| RGB | rgb(3, 102, 212) |
| HSL | hsl(212, 97%, 42%) |
| OKLCH | oklch(52.8% 0.187 257.2) |
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 #0366D4 | 5.44:1 | AA | Lc -81.7 | Fine for body text |
| Black text on #0366D4 | 3.85:1 | AA large text | Lc 27.7 | Dividers and decoration only |
| #0366D4 text on white | 5.44:1 | AA | Lc 76.4 | Fine for body text |
| #0366D4 text on black | 3.85:1 | AA large text | Lc -25.4 | 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
#E0EBFB
oklch(93.7% 0.025 257.6)
-
Step 200
200
#C6DBF9
oklch(88.5% 0.047 257.3)
-
Step 300
300
#9EC3F7
oklch(80.9% 0.084 256.9)
-
Step 400
400
#68A2F3
oklch(70.7% 0.134 256.9)
-
Step 500
500
#3C88EF
oklch(63.1% 0.172 257)
-
Step 600
600 (this color)
#0366D4
oklch(52.8% 0.187 257.2)
-
Step 700
700
#025CC0
oklch(49.1% 0.173 257)
-
Step 800
800
#0A4C9B
oklch(42.7% 0.143 256.9)
-
Step 900
900
#13407C
oklch(37.7% 0.113 257.2)
-
Step 950
950
#0D2648
oklch(27% 0.07 257)
#0366D4 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) | #1073D8 | 0.035 |
| Deuteranopia (no green cones) | #0061D2 | 0.013 |
| Tritanopia (no blue cones) | #008193 | 0.140 |
| Achromatopsia (no color) | #6A6A6A | 0.187 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0366D4
#0366D4
oklch(52.8% 0.187 257.2)
- #8E6100
#8E6100
oklch(52.7% 0.11 77.1)
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 #0366D4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Azul #1D5DEC ΔE 0.043
- Royal Blue #4169E1 ΔE 0.044
- Cerulean Blue #056EEE ΔE 0.044
- Mid Blue #276AB3 ΔE 0.055
- Warm Blue #4B57DB ΔE 0.056
- Neon Blue #4361EE ΔE 0.057
- Bright Blue #0165FC ΔE 0.061
- Windows Blue #3778BF ΔE 0.070
Use #0366D4 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.