#3B66E3
Closest named color: Royal Blue (#4169E1). oklch(55.3% 0.196 265.8), rgb(59, 102, 227).
Aa
White text reads best on this color (5.00:1).
About this color
#3B66E3 is a medium-dark, vivid blue. In OKLCH its lightness is 55%, its chroma 0.196 and its hue 266°. 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 5.00:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.196) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.19:1 |
| White text | 5.00:1 |
Values
| HEX | #3B66E3 |
| RGB | rgb(59, 102, 227) |
| HSL | hsl(225, 75%, 56%) |
| OKLCH | oklch(55.3% 0.196 265.8) |
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 #3B66E3 | 5.00:1 | AA | Lc -79.5 | Fine for body text |
| Black text on #3B66E3 | 4.19:1 | AA large text | Lc 30.0 | Dividers and decoration only |
| #3B66E3 text on white | 5.00:1 | AA | Lc 74.1 | Content text, not long reading |
| #3B66E3 text on black | 4.19:1 | AA large text | Lc -27.6 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFC
oklch(93.6% 0.026 266.6)
-
Step 200
200
#CAD9FB
oklch(88.5% 0.05 266.5)
-
Step 300
300
#A6C0FB
oklch(81% 0.089 266)
-
Step 400
400
#779DF8
oklch(70.8% 0.14 265.8)
-
Step 500
500
#5581F5
oklch(63.1% 0.18 265.8)
-
Step 600
600 (this color)
#3B66E3
oklch(55.3% 0.196 265.8)
-
Step 700
700
#2F55C6
oklch(49.2% 0.182 265.8)
-
Step 800
800
#2746A0
oklch(42.7% 0.151 265.8)
-
Step 900
900
#233C7F
oklch(37.7% 0.118 265.6)
-
Step 950
950
#15244A
oklch(27% 0.073 265.6)
#3B66E3 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) | #0077E7 | 0.045 |
| Deuteranopia (no green cones) | #0068E1 | 0.029 |
| Tritanopia (no blue cones) | #00859B | 0.155 |
| Achromatopsia (no color) | #6F6F6F | 0.196 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B66E3
#3B66E3
oklch(55.3% 0.196 265.8)
- #906C00
#906C00
oklch(55.2% 0.113 85.4)
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 #3B66E3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.011
- Neon Blue #4361EE ΔE 0.022
- Cerulean Blue #056EEE ΔE 0.032
- Azul #1D5DEC ΔE 0.036
- Warm Blue #4B57DB ΔE 0.037
- Bright Blue #0165FC ΔE 0.047
- Dark Periwinkle #665FD1 ΔE 0.058
- Clear Blue #247AFD ΔE 0.059
Use #3B66E3 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.