#366BDF
Closest named color: Royal Blue (#4169E1). oklch(55.8% 0.186 263.2), rgb(54, 107, 223).
Aa
White text reads best on this color (4.85:1).
About this color
#366BDF is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.186 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.011 away. White text reads best on it, at 4.85:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.186) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.32:1 |
| White text | 4.85:1 |
Values
| HEX | #366BDF |
| RGB | rgb(54, 107, 223) |
| HSL | hsl(221, 73%, 54%) |
| OKLCH | oklch(55.8% 0.186 263.2) |
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 #366BDF | 4.85:1 | AA | Lc -78.6 | Fine for body text |
| Black text on #366BDF | 4.32:1 | AA large text | Lc 30.9 | Non-text elements, placeholder text |
| #366BDF text on white | 4.85:1 | AA | Lc 73.2 | Content text, not long reading |
| #366BDF text on black | 4.32:1 | AA large text | Lc -28.5 | 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
#E1EAFB
oklch(93.5% 0.025 263.3)
-
Step 200
200
#C9DAF9
oklch(88.5% 0.047 262.5)
-
Step 300
300
#A4C1F8
oklch(80.9% 0.084 263)
-
Step 400
400
#749FF4
oklch(70.8% 0.134 263)
-
Step 500
500
#5084F0
oklch(63.1% 0.172 263.1)
-
Step 600
600 (this color)
#366BDF
oklch(55.8% 0.186 263.2)
-
Step 700
700
#2858C1
oklch(49.1% 0.173 263.1)
-
Step 800
800
#22499C
oklch(42.8% 0.143 262.9)
-
Step 900
900
#203E7C
oklch(37.7% 0.111 262.8)
-
Step 950
950
#132549
oklch(27.1% 0.071 262.6)
#366BDF 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) | #187AE3 | 0.038 |
| Deuteranopia (no green cones) | #006ADD | 0.026 |
| Tritanopia (no blue cones) | #00879B | 0.146 |
| Achromatopsia (no color) | #717171 | 0.187 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #366BDF
#366BDF
oklch(55.8% 0.186 263.2)
- #946C00
#946C00
oklch(55.7% 0.115 82.9)
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 #366BDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.011
- Cerulean Blue #056EEE ΔE 0.030
- Neon Blue #4361EE ΔE 0.034
- Azul #1D5DEC ΔE 0.046
- Warm Blue #4B57DB ΔE 0.048
- Bright Blue #0165FC ΔE 0.053
- Clear Blue #247AFD ΔE 0.055
- Dark Periwinkle #665FD1 ΔE 0.061
Use #366BDF 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.