#366ECE
Closest named color: Royal Blue (#4169E1). oklch(55.2% 0.16 260.4), rgb(54, 110, 206).
Aa
White text reads best on this color (4.90:1).
About this color
#366ECE is a medium-dark, vivid blue. In OKLCH its lightness is 55%, its chroma 0.160 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.034 away. White text reads best on it, at 4.90:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.160) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.27:1 |
| White text | 4.90:1 |
Values
| HEX | #366ECE |
| RGB | rgb(54, 110, 206) |
| HSL | hsl(218, 61%, 51%) |
| OKLCH | oklch(55.2% 0.16 260.4) |
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 #366ECE | 4.90:1 | AA | Lc -79.0 | Fine for body text |
| Black text on #366ECE | 4.27:1 | AA large text | Lc 30.5 | Non-text elements, placeholder text |
| #366ECE text on white | 4.90:1 | AA | Lc 73.6 | Content text, not long reading |
| #366ECE text on black | 4.27:1 | AA large text | Lc -28.1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF8
oklch(93.5% 0.021 261.8)
-
Step 200
200
#CADAF4
oklch(88.4% 0.04 260.1)
-
Step 300
300
#A6C2F0
oklch(80.9% 0.072 260.3)
-
Step 400
400
#76A1E8
oklch(70.7% 0.115 260.1)
-
Step 500
500
#5387E1
oklch(63% 0.147 260.6)
-
Step 600
600 (this color)
#366ECE
oklch(55.2% 0.16 260.4)
-
Step 700
700
#2A5CB4
oklch(49% 0.15 260.8)
-
Step 800
800
#244C91
oklch(42.7% 0.123 260.5)
-
Step 900
900
#224074
oklch(37.7% 0.096 260.6)
-
Step 950
950
#142644
oklch(27% 0.061 260.1)
#366ECE 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) | #3B78D2 | 0.028 |
| Deuteranopia (no green cones) | #146ACC | 0.025 |
| Tritanopia (no blue cones) | #008594 | 0.126 |
| Achromatopsia (no color) | #717171 | 0.160 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #366ECE
#366ECE
oklch(55.2% 0.16 260.4)
- #946900
#946900
oklch(55.1% 0.114 80.3)
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 #366ECE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.034
- Windows Blue #3778BF ΔE 0.039
- Mid Blue #276AB3 ΔE 0.045
- French Blue #436BAD ΔE 0.051
- Cerulean Blue #056EEE ΔE 0.052
- Neon Blue #4361EE ΔE 0.061
- Warm Blue #4B57DB ΔE 0.062
- Dark Periwinkle #665FD1 ΔE 0.063
Use #366ECE 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.