#3F63BD
Closest named color: Mid Blue (#276AB3). oklch(52.1% 0.147 265.2), rgb(63, 99, 189).
Aa
White text reads best on this color (5.62:1).
About this color
#3F63BD is a medium-dark, vivid blue. In OKLCH its lightness is 52%, its chroma 0.147 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.032 away. White text reads best on it, at 5.62:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.147) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.73:1 |
| White text | 5.62:1 |
Values
| HEX | #3F63BD |
| RGB | rgb(63, 99, 189) |
| HSL | hsl(223, 50%, 49%) |
| OKLCH | oklch(52.1% 0.147 265.2) |
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 #3F63BD | 5.62:1 | AA | Lc -83.1 | Fine for body text |
| Black text on #3F63BD | 3.73:1 | AA large text | Lc 26.2 | Dividers and decoration only |
| #3F63BD text on white | 5.62:1 | AA | Lc 77.8 | Fine for body text |
| #3F63BD text on black | 3.73:1 | AA large text | Lc -23.9 | 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 700.
-
Step 50
50
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E3EAF8
oklch(93.6% 0.02 264.5)
-
Step 200
200
#CDD9F4
oklch(88.5% 0.039 266.5)
-
Step 300
300
#AAC0F0
oklch(80.8% 0.072 265.6)
-
Step 400
400
#7E9FE8
oklch(70.8% 0.114 265.1)
-
Step 500
500
#5E85E1
oklch(63.1% 0.145 265.2)
-
Step 600
600
#456CCF
oklch(55.5% 0.159 265.4)
-
Step 700
700 (this color)
#3F63BD
oklch(52.1% 0.147 265.2)
-
Step 800
800
#2E4A91
oklch(42.7% 0.122 265.4)
-
Step 900
900
#293F74
oklch(37.9% 0.095 265.2)
-
Step 950
950
#182544
oklch(27% 0.061 265.4)
#3F63BD 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) | #346DC0 | 0.027 |
| Deuteranopia (no green cones) | #1962BB | 0.030 |
| Tritanopia (no blue cones) | #007887 | 0.121 |
| Achromatopsia (no color) | #676767 | 0.147 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F63BD
#3F63BD
oklch(52.1% 0.147 265.2)
- #856300
#856300
oklch(52% 0.107 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 #3F63BD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.032
- French Blue #436BAD ΔE 0.037
- Iris #6258C4 ΔE 0.052
- Windows Blue #3778BF ΔE 0.056
- Royal Blue #4169E1 ΔE 0.057
- Warm Blue #4B57DB ΔE 0.058
- Dark Periwinkle #665FD1 ΔE 0.060
- Flat Blue #3C73A8 ΔE 0.060
Use #3F63BD 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.