#3F74E8
Closest named color: Royal Blue (#4169E1). oklch(58.6% 0.185 263.3), rgb(63, 116, 232).
Aa
Black text reads best on this color (4.87:1).
About this color
#3F74E8 is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.185 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.028 away. Black text reads best on it, at 4.87:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.185) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.87:1 |
| White text | 4.30:1 |
Values
| HEX | #3F74E8 |
| RGB | rgb(63, 116, 232) |
| HSL | hsl(221, 79%, 58%) |
| OKLCH | oklch(58.6% 0.185 263.3) |
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 #3F74E8 | 4.30:1 | AA large text | Lc -74.9 | Content text, not long reading |
| Black text on #3F74E8 | 4.87:1 | AA | Lc 34.7 | Non-text elements, placeholder text |
| #3F74E8 text on white | 4.30:1 | AA large text | Lc 69.4 | Content text, not long reading |
| #3F74E8 text on black | 4.87:1 | AA | Lc -32.3 | Non-text elements, placeholder text |
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
#C9DAF9
oklch(88.5% 0.047 262.5)
-
Step 300
300
#A5C1F7
oklch(80.9% 0.083 263.3)
-
Step 400
400
#759FF3
oklch(70.8% 0.132 263.2)
-
Step 500
500
#5184EF
oklch(63.1% 0.17 263.2)
-
Step 600
600 (this color)
#3F74E8
oklch(58.6% 0.185 263.3)
-
Step 700
700
#2958C0
oklch(49.1% 0.172 263.2)
-
Step 800
800
#23499C
oklch(42.8% 0.142 263.2)
-
Step 900
900
#213E7C
oklch(37.8% 0.111 263.2)
-
Step 950
950
#142548
oklch(27.1% 0.069 263.1)
#3F74E8 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) | #2D82EC | 0.035 |
| Deuteranopia (no green cones) | #0072E6 | 0.032 |
| Tritanopia (no blue cones) | #0090A3 | 0.147 |
| Achromatopsia (no color) | #7A7A7A | 0.185 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F74E8
#3F74E8
oklch(58.6% 0.185 263.3)
- #9E7400
#9E7400
oklch(58.5% 0.12 83.2)
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 #3F74E8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.028
- Clear Blue #247AFD ΔE 0.035
- Cerulean Blue #056EEE ΔE 0.037
- Neon Blue #4361EE ΔE 0.046
- Cornflower #6A79F7 ΔE 0.056
- Bright Blue #0165FC ΔE 0.060
- Azul #1D5DEC ΔE 0.066
- Windows Blue #3778BF ΔE 0.066
Use #3F74E8 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.