#366FDF
Closest named color: Royal Blue (#4169E1). oklch(56.6% 0.182 262.1), rgb(54, 111, 223).
Aa
White text reads best on this color (4.67:1).
About this color
#366FDF is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.182 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.017 away. White text reads best on it, at 4.67:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.182) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.49:1 |
| White text | 4.67:1 |
Values
| HEX | #366FDF |
| RGB | rgb(54, 111, 223) |
| HSL | hsl(220, 73%, 54%) |
| OKLCH | oklch(56.6% 0.182 262.1) |
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 #366FDF | 4.67:1 | AA | Lc -77.4 | Fine for body text |
| Black text on #366FDF | 4.49:1 | AA large text | Lc 32.1 | Non-text elements, placeholder text |
| #366FDF text on white | 4.67:1 | AA | Lc 72.0 | Content text, not long reading |
| #366FDF text on black | 4.49:1 | AA large text | Lc -29.7 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EAFA
oklch(93.5% 0.024 262.1)
-
Step 200
200
#C9DAF8
oklch(88.5% 0.045 261.9)
-
Step 300
300
#A4C1F6
oklch(80.8% 0.082 262.3)
-
Step 400
400
#739FF2
oklch(70.6% 0.131 262.3)
-
Step 500
500
#4F85ED
oklch(63.1% 0.167 262.1)
-
Step 600
600 (this color)
#366FDF
oklch(56.6% 0.182 262.1)
-
Step 700
700
#2659BF
oklch(49.1% 0.17 262.2)
-
Step 800
800
#214A9A
oklch(42.8% 0.139 262)
-
Step 900
900
#1F3E7B
oklch(37.6% 0.11 262.2)
-
Step 950
950
#132548
oklch(27% 0.069 262.3)
#366FDF 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) | #297CE3 | 0.033 |
| Deuteranopia (no green cones) | #006DDD | 0.026 |
| Tritanopia (no blue cones) | #008A9C | 0.143 |
| Achromatopsia (no color) | #747474 | 0.182 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #366FDF
#366FDF
oklch(56.6% 0.182 262.1)
- #986E00
#986E00
oklch(56.6% 0.117 82)
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 #366FDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.017
- Cerulean Blue #056EEE ΔE 0.031
- Neon Blue #4361EE ΔE 0.042
- Clear Blue #247AFD ΔE 0.050
- Azul #1D5DEC ΔE 0.054
- Warm Blue #4B57DB ΔE 0.057
- Bright Blue #0165FC ΔE 0.057
- Windows Blue #3778BF ΔE 0.058
Use #366FDF 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.