#366CEE
Closest named color: Royal Blue (#4169E1). oklch(57.1% 0.205 264), rgb(54, 108, 238).
Aa
White text reads best on this color (4.62:1).
About this color
#366CEE is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.205 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.022 away. White text reads best on it, at 4.62:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.205) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.53:1 |
| White text | 4.62:1 |
Values
| HEX | #366CEE |
| RGB | rgb(54, 108, 238) |
| HSL | hsl(222, 84%, 57%) |
| OKLCH | oklch(57.1% 0.205 264) |
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 #366CEE | 4.62:1 | AA | Lc -77.0 | Fine for body text |
| Black text on #366CEE | 4.53:1 | AA | Lc 32.5 | Non-text elements, placeholder text |
| #366CEE text on white | 4.62:1 | AA | Lc 71.6 | Content text, not long reading |
| #366CEE text on black | 4.53:1 | AA | Lc -30.1 | Non-text elements, placeholder text |
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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C8DAFC
oklch(88.6% 0.051 263.2)
-
Step 300
300
#A2C0FD
oklch(80.8% 0.093 264.1)
-
Step 400
400
#719DFC
oklch(70.6% 0.148 264.2)
-
Step 500
500
#4D81FA
oklch(63.1% 0.189 264.2)
-
Step 600
600 (this color)
#366CEE
oklch(57.1% 0.205 264)
-
Step 700
700
#2555CA
oklch(49.1% 0.189 263.8)
-
Step 800
800
#2046A4
oklch(42.7% 0.158 264.1)
-
Step 900
900
#1E3C82
oklch(37.7% 0.124 263.9)
-
Step 950
950
#12244C
oklch(27% 0.078 263.8)
#366CEE 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) | #007EF3 | 0.045 |
| Deuteranopia (no green cones) | #006DEB | 0.024 |
| Tritanopia (no blue cones) | #008CA2 | 0.160 |
| Achromatopsia (no color) | #757575 | 0.205 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #366CEE
#366CEE
oklch(57.1% 0.205 264)
- #987000
#987000
oklch(57% 0.117 83.7)
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 #366CEE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.022
- Cerulean Blue #056EEE ΔE 0.022
- Neon Blue #4361EE ΔE 0.026
- Bright Blue #0165FC ΔE 0.038
- Clear Blue #247AFD ΔE 0.039
- Azul #1D5DEC ΔE 0.043
- Warm Blue #4B57DB ΔE 0.056
- Cornflower #6A79F7 ΔE 0.070
Use #366CEE 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.