#3F81DB
Closest named color: Dark Sky Blue (#448EE4). oklch(60.5% 0.153 256.9), rgb(63, 129, 219).
Aa
Black text reads best on this color (5.37:1).
About this color
#3F81DB is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.153 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.037 away. Black text reads best on it, at 5.37:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.153) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.37:1 |
| White text | 3.90:1 |
Values
| HEX | #3F81DB |
| RGB | rgb(63, 129, 219) |
| HSL | hsl(215, 68%, 55%) |
| OKLCH | oklch(60.5% 0.153 256.9) |
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 #3F81DB | 3.90:1 | AA large text | Lc -71.7 | Content text, not long reading |
| Black text on #3F81DB | 5.37:1 | AA | Lc 37.9 | Non-text elements, placeholder text |
| #3F81DB text on white | 3.90:1 | AA large text | Lc 66.2 | Content text, not long reading |
| #3F81DB text on black | 5.37:1 | AA | Lc -35.5 | 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 500.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF9
oklch(93.7% 0.022 256.7)
-
Step 200
200
#C8DBF5
oklch(88.5% 0.041 256.2)
-
Step 300
300
#A2C3F1
oklch(80.9% 0.075 256.7)
-
Step 400
400
#6FA2EA
oklch(70.6% 0.119 257.1)
-
Step 500
500 (this color)
#3F81DB
oklch(60.5% 0.153 256.9)
-
Step 600
600
#2771D2
oklch(55.6% 0.166 257)
-
Step 700
700
#195EB6
oklch(49.1% 0.155 257)
-
Step 800
800
#184D93
oklch(42.7% 0.128 257.1)
-
Step 900
900
#1A4175
oklch(37.7% 0.099 256.7)
-
Step 950
950
#102645
oklch(26.9% 0.064 257.3)
#3F81DB 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) | #5689DF | 0.033 |
| Deuteranopia (no green cones) | #3C7AD9 | 0.019 |
| Tritanopia (no blue cones) | #0096A3 | 0.120 |
| Achromatopsia (no color) | #818181 | 0.153 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F81DB
#3F81DB
oklch(60.5% 0.153 256.9)
- #AB7600
#AB7600
oklch(60.5% 0.126 77.4)
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 #3F81DB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.037
- Water Blue #0E87CC ΔE 0.039
- Windows Blue #3778BF ΔE 0.048
- Soft Blue #6488EA ΔE 0.049
- Cool Blue #4984B8 ΔE 0.057
- Clear Blue #247AFD ΔE 0.059
- Chefchaouen Blue #4895EF ΔE 0.059
- Steel Blue #4682B4 ΔE 0.061
Use #3F81DB 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.