#3664D9
Closest named color: Royal Blue (#4169E1). oklch(53.9% 0.187 264.6), rgb(54, 100, 217).
Aa
White text reads best on this color (5.27:1).
About this color
#3664D9 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.187 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.021 away. White text reads best on it, at 5.27:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.187) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 3.98:1 |
| White text | 5.27:1 |
Values
| HEX | #3664D9 |
| RGB | rgb(54, 100, 217) |
| HSL | hsl(223, 68%, 53%) |
| OKLCH | oklch(53.9% 0.187 264.6) |
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 #3664D9 | 5.27:1 | AA | Lc -81.1 | Fine for body text |
| Black text on #3664D9 | 3.98:1 | AA large text | Lc 28.4 | Dividers and decoration only |
| #3664D9 text on white | 5.27:1 | AA | Lc 75.7 | Fine for body text |
| #3664D9 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
#E2EAFB
oklch(93.6% 0.025 265.6)
-
Step 200
200
#CAD9F9
oklch(88.4% 0.047 265.5)
-
Step 300
300
#A6C0F8
oklch(80.8% 0.085 265.2)
-
Step 400
400
#769EF4
oklch(70.7% 0.134 264.3)
-
Step 500
500
#5483F0
oklch(63.1% 0.171 264.5)
-
Step 600
600 (this color)
#3664D9
oklch(53.9% 0.187 264.6)
-
Step 700
700
#2D57C1
oklch(49.1% 0.173 264.5)
-
Step 800
800
#26489C
oklch(42.7% 0.143 264.5)
-
Step 900
900
#233D7C
oklch(37.7% 0.112 264.7)
-
Step 950
950
#152449
oklch(27% 0.072 265.3)
#3664D9 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) | #0074DD | 0.042 |
| Deuteranopia (no green cones) | #0065D7 | 0.026 |
| Tritanopia (no blue cones) | #008195 | 0.148 |
| Achromatopsia (no color) | #6C6C6C | 0.187 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3664D9
#3664D9
oklch(53.9% 0.187 264.6)
- #8C6800
#8C6800
oklch(53.9% 0.111 84.6)
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 #3664D9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.021
- Warm Blue #4B57DB ΔE 0.034
- Neon Blue #4361EE ΔE 0.035
- Azul #1D5DEC ΔE 0.039
- Cerulean Blue #056EEE ΔE 0.041
- Bright Blue #0165FC ΔE 0.057
- Dark Periwinkle #665FD1 ΔE 0.058
- Iris #6258C4 ΔE 0.063
Use #3664D9 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.