#3666FA
Closest named color: Neon Blue (#4361EE). oklch(56.9% 0.227 265.6), rgb(54, 102, 250).
Aa
White text reads best on this color (4.73:1).
About this color
#3666FA is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.227 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Neon Blue (#4361EE), ΔE 0.023 away. White text reads best on it, at 4.73:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.227) |
| Temperature | cool |
| Nearest name | Neon Blue (#4361EE) |
| Black text | 4.43:1 |
| White text | 4.73:1 |
Values
| HEX | #3666FA |
| RGB | rgb(54, 102, 250) |
| HSL | hsl(225, 95%, 60%) |
| OKLCH | oklch(56.9% 0.227 265.6) |
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 #3666FA | 4.73:1 | AA | Lc -77.6 | Fine for body text |
| Black text on #3666FA | 4.43:1 | AA large text | Lc 31.9 | Non-text elements, placeholder text |
| #3666FA text on white | 4.73:1 | AA | Lc 72.2 | Content text, not long reading |
| #3666FA text on black | 4.43:1 | AA large text | Lc -29.5 | 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
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E0EAFE
oklch(93.6% 0.029 264.4)
-
Step 200
200
#C8D9FF
oklch(88.5% 0.056 266.2)
-
Step 300
300
#A3C0FF
oklch(80.9% 0.095 265.2)
-
Step 400
400
#739CFF
oklch(70.7% 0.152 265.7)
-
Step 500
500
#4F7FFF
oklch(63.1% 0.197 265.6)
-
Step 600
600 (this color)
#3666FA
oklch(56.9% 0.227 265.6)
-
Step 700
700
#264FD6
oklch(49.1% 0.212 265.6)
-
Step 800
800
#2042AD
oklch(42.7% 0.175 265.6)
-
Step 900
900
#1E3A89
oklch(37.8% 0.136 265.4)
-
Step 950
950
#122350
oklch(27.1% 0.086 265.4)
#3666FA 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) | #007DFF | 0.054 |
| Deuteranopia (no green cones) | #006AF7 | 0.024 |
| Tritanopia (no blue cones) | #008CA6 | 0.177 |
| Achromatopsia (no color) | #737373 | 0.227 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3666FA
#3666FA
oklch(56.9% 0.227 265.6)
- #967100
#967100
oklch(57% 0.117 85.7)
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 #3666FA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Neon Blue #4361EE ΔE 0.023
- Bright Blue #0165FC ΔE 0.025
- Cerulean Blue #056EEE ΔE 0.033
- Azul #1D5DEC ΔE 0.037
- Royal Blue #4169E1 ΔE 0.040
- Clear Blue #247AFD ΔE 0.046
- Electric Blue #0652FF ΔE 0.055
- Warm Blue #4B57DB ΔE 0.058
Use #3666FA 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.