#3366D3
Closest named color: Royal Blue (#4169E1). oklch(53.8% 0.177 263), rgb(51, 102, 211).
Aa
White text reads best on this color (5.27:1).
About this color
#3366D3 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.177 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.027 away. White text reads best on it, at 5.27:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.177) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 3.98:1 |
| White text | 5.27:1 |
Values
| HEX | #3366D3 |
| RGB | rgb(51, 102, 211) |
| HSL | hsl(221, 65%, 51%) |
| OKLCH | oklch(53.8% 0.177 263) |
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 #3366D3 | 5.27:1 | AA | Lc -81.1 | Fine for body text |
| Black text on #3366D3 | 3.98:1 | AA large text | Lc 28.3 | Dividers and decoration only |
| #3366D3 text on white | 5.27:1 | AA | Lc 75.7 | Fine for body text |
| #3366D3 text on black | 3.98:1 | AA large text | Lc -26.0 | 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
#A6C1F5
oklch(80.9% 0.08 263.3)
-
Step 400
400
#769FF0
oklch(70.7% 0.128 263.1)
-
Step 500
500
#5385EB
oklch(63.2% 0.163 262.9)
-
Step 600
600 (this color)
#3366D3
oklch(53.8% 0.177 263)
-
Step 700
700
#2B59BC
oklch(49% 0.164 263)
-
Step 800
800
#244998
oklch(42.5% 0.137 263)
-
Step 900
900
#223E79
oklch(37.6% 0.106 263.2)
-
Step 950
950
#142547
oklch(27% 0.067 262.7)
#3366D3 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) | #1C73D7 | 0.033 |
| Deuteranopia (no green cones) | #0065D1 | 0.025 |
| Tritanopia (no blue cones) | #008093 | 0.138 |
| Achromatopsia (no color) | #6C6C6C | 0.177 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3366D3
#3366D3
oklch(53.8% 0.177 263)
- #8D6700
#8D6700
oklch(53.8% 0.111 83.1)
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 #3366D3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.027
- Warm Blue #4B57DB ΔE 0.042
- Cerulean Blue #056EEE ΔE 0.046
- Neon Blue #4361EE ΔE 0.046
- Azul #1D5DEC ΔE 0.048
- Mid Blue #276AB3 ΔE 0.054
- Dark Periwinkle #665FD1 ΔE 0.060
- Windows Blue #3778BF ΔE 0.062
Use #3366D3 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.