#366CD8
Closest named color: Royal Blue (#4169E1). oklch(55.5% 0.176 262.3), rgb(54, 108, 216).
Aa
White text reads best on this color (4.89:1).
About this color
#366CD8 is a medium-dark, vivid blue. In OKLCH its lightness is 55%, its chroma 0.176 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.019 away. White text reads best on it, at 4.89:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.176) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.29:1 |
| White text | 4.89:1 |
Values
| HEX | #366CD8 |
| RGB | rgb(54, 108, 216) |
| HSL | hsl(220, 68%, 53%) |
| OKLCH | oklch(55.5% 0.176 262.3) |
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 #366CD8 | 4.89:1 | AA | Lc -78.9 | Fine for body text |
| Black text on #366CD8 | 4.29:1 | AA large text | Lc 30.6 | Non-text elements, placeholder text |
| #366CD8 text on white | 4.89:1 | AA | Lc 73.4 | Content text, not long reading |
| #366CD8 text on black | 4.29:1 | AA large text | Lc -28.3 | 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
#F2F6FD
oklch(97.2% 0.01 261.8)
-
Step 100
100
#E2EAFA
oklch(93.6% 0.023 264.5)
-
Step 200
200
#CADAF7
oklch(88.5% 0.044 262.4)
-
Step 300
300
#A5C1F5
oklch(80.9% 0.08 262.6)
-
Step 400
400
#759FEF
oklch(70.6% 0.127 262.5)
-
Step 500
500
#5185EA
oklch(63% 0.162 262.2)
-
Step 600
600 (this color)
#366CD8
oklch(55.5% 0.176 262.3)
-
Step 700
700
#295ABC
oklch(49.2% 0.164 262.2)
-
Step 800
800
#234A98
oklch(42.7% 0.136 262.3)
-
Step 900
900
#213F79
oklch(37.8% 0.105 262.1)
-
Step 950
950
#142547
oklch(27% 0.067 262.7)
#366CD8 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) | #2A79DC | 0.033 |
| Deuteranopia (no green cones) | #006AD6 | 0.027 |
| Tritanopia (no blue cones) | #008698 | 0.138 |
| Achromatopsia (no color) | #717171 | 0.176 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #366CD8
#366CD8
oklch(55.5% 0.176 262.3)
- #946B00
#946B00
oklch(55.5% 0.114 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 #366CD8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.019
- Cerulean Blue #056EEE ΔE 0.038
- Neon Blue #4361EE ΔE 0.045
- Warm Blue #4B57DB ΔE 0.052
- Azul #1D5DEC ΔE 0.053
- Windows Blue #3778BF ΔE 0.054
- Dark Periwinkle #665FD1 ΔE 0.060
- Mid Blue #276AB3 ΔE 0.060
Use #366CD8 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.