#3F63B3
Closest named color: Mid Blue (#276AB3). oklch(51.4% 0.133 264.1), rgb(63, 99, 179).
Aa
White text reads best on this color (5.75:1).
About this color
#3F63B3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 51%, its chroma 0.133 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.025 away. White text reads best on it, at 5.75:1.
| Hue family | Blues |
| Lightness | medium-dark (51%) |
| Chroma | moderately saturated (0.133) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.64:1 |
| White text | 5.75:1 |
Values
| HEX | #3F63B3 |
| RGB | rgb(63, 99, 179) |
| HSL | hsl(221, 48%, 47%) |
| OKLCH | oklch(51.4% 0.133 264.1) |
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 #3F63B3 | 5.75:1 | AA | Lc -83.8 | Fine for body text |
| Black text on #3F63B3 | 3.64:1 | AA large text | Lc 25.5 | Dividers and decoration only |
| #3F63B3 text on white | 5.75:1 | AA | Lc 78.5 | Fine for body text |
| #3F63B3 text on black | 3.64:1 | AA large text | Lc -23.2 | 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 700.
-
Step 50
50
#F2F5FB
oklch(97% 0.009 264.5)
-
Step 100
100
#E4EAF7
oklch(93.6% 0.019 266)
-
Step 200
200
#CDD9F2
oklch(88.4% 0.037 265.1)
-
Step 300
300
#ACC1EB
oklch(80.9% 0.064 264.1)
-
Step 400
400
#80A0E1
oklch(70.8% 0.102 263.9)
-
Step 500
500
#6087D9
oklch(63.2% 0.131 263.8)
-
Step 600
600
#476FC6
oklch(55.6% 0.142 263.8)
-
Step 700
700 (this color)
#3F63B3
oklch(51.4% 0.133 264.1)
-
Step 800
800
#2F4C8B
oklch(42.8% 0.11 263.8)
-
Step 900
900
#2A406F
oklch(37.8% 0.085 263.9)
-
Step 950
950
#192641
oklch(27.2% 0.054 263.7)
#3F63B3 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) | #3D6CB6 | 0.024 |
| Deuteranopia (no green cones) | #2A61B1 | 0.022 |
| Tritanopia (no blue cones) | #007582 | 0.111 |
| Achromatopsia (no color) | #666666 | 0.133 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F63B3
#3F63B3
oklch(51.4% 0.133 264.1)
- #846100
#846100
oklch(51.5% 0.106 83.8)
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 #3F63B3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.025
- French Blue #436BAD ΔE 0.027
- Dusky Blue #475F94 ΔE 0.049
- Flat Blue #3C73A8 ΔE 0.052
- Denim Blue #3B5B92 ΔE 0.055
- Muted Blue #3B719F ΔE 0.056
- Windows Blue #3778BF ΔE 0.057
- Iris #6258C4 ΔE 0.059
Use #3F63B3 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.