#3663E4
Closest named color: Royal Blue (#4169E1). oklch(54.6% 0.202 265.4), rgb(54, 99, 228).
Aa
White text reads best on this color (5.17:1).
About this color
#3663E4 is a medium-dark, vivid blue. In OKLCH its lightness is 55%, its chroma 0.202 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.020 away. White text reads best on it, at 5.17:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.202) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.06:1 |
| White text | 5.17:1 |
Values
| HEX | #3663E4 |
| RGB | rgb(54, 99, 228) |
| HSL | hsl(224, 76%, 55%) |
| OKLCH | oklch(54.6% 0.202 265.4) |
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 #3663E4 | 5.17:1 | AA | Lc -80.4 | Fine for body text |
| Black text on #3663E4 | 4.06:1 | AA large text | Lc 29.1 | Dividers and decoration only |
| #3663E4 text on white | 5.17:1 | AA | Lc 75.0 | Fine for body text |
| #3663E4 text on black | 4.06:1 | AA large text | Lc -26.7 | 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
#F1F5FE
oklch(97% 0.013 266.7)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C9D9FC
oklch(88.5% 0.051 265.9)
-
Step 300
300
#A4C0FC
oklch(80.9% 0.091 265)
-
Step 400
400
#749DFB
oklch(70.7% 0.145 265.1)
-
Step 500
500
#5281F9
oklch(63.2% 0.186 265.3)
-
Step 600
600 (this color)
#3663E4
oklch(54.6% 0.202 265.4)
-
Step 700
700
#2C54C9
oklch(49.1% 0.188 265.5)
-
Step 800
800
#2546A3
oklch(42.8% 0.155 265.4)
-
Step 900
900
#223C81
oklch(37.8% 0.121 265.4)
-
Step 950
950
#14244C
oklch(27.1% 0.077 265.2)
#3663E4 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) | #0075E8 | 0.045 |
| Deuteranopia (no green cones) | #0065E1 | 0.026 |
| Tritanopia (no blue cones) | #00839A | 0.158 |
| Achromatopsia (no color) | #6D6D6D | 0.203 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3663E4
#3663E4
oklch(54.6% 0.202 265.4)
- #8E6A00
#8E6A00
oklch(54.6% 0.112 85)
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 #3663E4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.020
- Neon Blue #4361EE ΔE 0.020
- Azul #1D5DEC ΔE 0.027
- Cerulean Blue #056EEE ΔE 0.033
- Warm Blue #4B57DB ΔE 0.034
- Bright Blue #0165FC ΔE 0.042
- Dark Periwinkle #665FD1 ΔE 0.063
- Electric Blue #0652FF ΔE 0.063
Use #3663E4 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.