#3663CE
Closest named color: Royal Blue (#4169E1). oklch(52.9% 0.173 264.2), rgb(54, 99, 206).
Aa
White text reads best on this color (5.47:1).
About this color
#3663CE is a medium-dark, vivid blue. In OKLCH its lightness is 53%, its chroma 0.173 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.035 away. White text reads best on it, at 5.47:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.173) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 3.83:1 |
| White text | 5.47:1 |
Values
| HEX | #3663CE |
| RGB | rgb(54, 99, 206) |
| HSL | hsl(222, 61%, 51%) |
| OKLCH | oklch(52.9% 0.173 264.2) |
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 #3663CE | 5.47:1 | AA | Lc -82.2 | Fine for body text |
| Black text on #3663CE | 3.83:1 | AA large text | Lc 27.2 | Dividers and decoration only |
| #3663CE text on white | 5.47:1 | AA | Lc 76.9 | Fine for body text |
| #3663CE text on black | 3.83:1 | AA large text | Lc -24.9 | 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
#CBDAF7
oklch(88.6% 0.043 263.7)
-
Step 300
300
#A7C1F4
oklch(80.9% 0.078 263.6)
-
Step 400
400
#799FEE
oklch(70.8% 0.124 263.9)
-
Step 500
500
#5784E9
oklch(63% 0.16 264.2)
-
Step 600
600 (this color)
#3663CE
oklch(52.9% 0.173 264.2)
-
Step 700
700
#3059BB
oklch(49.1% 0.162 264.2)
-
Step 800
800
#284997
oklch(42.6% 0.134 264.2)
-
Step 900
900
#243E78
oklch(37.6% 0.104 263.9)
-
Step 950
950
#162546
oklch(27.1% 0.065 264.1)
#3663CE 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) | #1A70D2 | 0.034 |
| Deuteranopia (no green cones) | #0063CC | 0.028 |
| Tritanopia (no blue cones) | #007D8F | 0.138 |
| Achromatopsia (no color) | #696969 | 0.174 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3663CE
#3663CE
oklch(52.9% 0.173 264.2)
- #896500
#896500
oklch(52.9% 0.109 84)
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 #3663CE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.035
- Warm Blue #4B57DB ΔE 0.040
- Mid Blue #276AB3 ΔE 0.050
- Neon Blue #4361EE ΔE 0.052
- Azul #1D5DEC ΔE 0.052
- Cerulean Blue #056EEE ΔE 0.055
- Iris #6258C4 ΔE 0.057
- Dark Periwinkle #665FD1 ΔE 0.058
Use #3663CE 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.