#0366E3
Closest named color: Azul (#1D5DEC). oklch(54% 0.206 258.8), rgb(3, 102, 227).
Aa
White text reads best on this color (5.23:1).
About this color
#0366E3 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.206 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Azul (#1D5DEC), ΔE 0.025 away. White text reads best on it, at 5.23:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.206) |
| Temperature | cool |
| Nearest name | Azul (#1D5DEC) |
| Black text | 4.01:1 |
| White text | 5.23:1 |
Values
| HEX | #0366E3 |
| RGB | rgb(3, 102, 227) |
| HSL | hsl(213, 97%, 45%) |
| OKLCH | oklch(54% 0.206 258.8) |
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 #0366E3 | 5.23:1 | AA | Lc -80.4 | Fine for body text |
| Black text on #0366E3 | 4.01:1 | AA large text | Lc 29.0 | Dividers and decoration only |
| #0366E3 text on white | 5.23:1 | AA | Lc 75.1 | Fine for body text |
| #0366E3 text on black | 4.01:1 | AA large text | Lc -26.7 | 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
#F0F6FE
oklch(97.1% 0.012 255.5)
-
Step 100
100
#DFEBFC
oklch(93.6% 0.026 257)
-
Step 200
200
#C5DBFC
oklch(88.6% 0.051 258.4)
-
Step 300
300
#9CC2FD
oklch(80.8% 0.094 259)
-
Step 400
400
#65A0FC
oklch(70.6% 0.149 259)
-
Step 500
500
#3885F9
oklch(63% 0.189 258.8)
-
Step 600
600 (this color)
#0366E3
oklch(54% 0.206 258.8)
-
Step 700
700
#0059C9
oklch(49.2% 0.189 258.8)
-
Step 800
800
#0649A3
oklch(42.7% 0.158 258.8)
-
Step 900
900
#113E82
oklch(37.7% 0.125 259.1)
-
Step 950
950
#0C254C
oklch(27% 0.079 259.2)
#0366E3 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) | #0076E7 | 0.041 |
| Deuteranopia (no green cones) | #0063E1 | 0.008 |
| Tritanopia (no blue cones) | #00869A | 0.157 |
| Achromatopsia (no color) | #6C6C6C | 0.206 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0366E3
#0366E3
oklch(54% 0.206 258.8)
- #916500
#916500
oklch(53.9% 0.112 78.8)
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 #0366E3, closest first.
No curated palette has a color within ΔE 0.04 of #0366E3.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Azul #1D5DEC ΔE 0.025
- Cerulean Blue #056EEE ΔE 0.026
- Royal Blue #4169E1 ΔE 0.037
- Bright Blue #0165FC ΔE 0.038
- Neon Blue #4361EE ΔE 0.041
- Warm Blue #4B57DB ΔE 0.054
- Electric Blue #0652FF ΔE 0.060
- Clear Blue #247AFD ΔE 0.066
Use #0366E3 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.