#3F81BA
Closest named color: Steel Blue (#4682B4). oklch(58.6% 0.111 247.1), rgb(63, 129, 186).
Aa
Black text reads best on this color (5.06:1).
About this color
#3F81BA is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.111 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.012 away. Black text reads best on it, at 5.06:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 5.06:1 |
| White text | 4.14:1 |
Values
| HEX | #3F81BA |
| RGB | rgb(63, 129, 186) |
| HSL | hsl(208, 49%, 49%) |
| OKLCH | oklch(58.6% 0.111 247.1) |
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 #3F81BA | 4.14:1 | AA large text | Lc -73.8 | Content text, not long reading |
| Black text on #3F81BA | 5.06:1 | AA | Lc 35.8 | Non-text elements, placeholder text |
| #3F81BA text on white | 4.14:1 | AA large text | Lc 68.3 | Content text, not long reading |
| #3F81BA text on black | 5.06:1 | AA | Lc -33.3 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#CBDBEB
oklch(88.4% 0.028 248.1)
-
Step 300
300
#A8C4E0
oklch(80.9% 0.05 248.4)
-
Step 400
400
#78A6D0
oklch(70.8% 0.079 246.7)
-
Step 500
500
#538FC4
oklch(63.2% 0.102 246.9)
-
Step 600
600 (this color)
#3F81BA
oklch(58.6% 0.111 247.1)
-
Step 700
700
#286598
oklch(49.2% 0.103 247.2)
-
Step 800
800
#22527B
oklch(42.6% 0.086 247.3)
-
Step 900
900
#224463
oklch(37.6% 0.067 248)
-
Step 950
950
#14283A
oklch(26.9% 0.043 247.2)
#3F81BA 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) | #6883BC | 0.044 |
| Deuteranopia (no green cones) | #5777B9 | 0.034 |
| Tritanopia (no blue cones) | #008F95 | 0.085 |
| Achromatopsia (no color) | #7C7C7C | 0.111 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F81BA
#3F81BA
oklch(58.6% 0.111 247.1)
- #A76E28
#A76E28
oklch(58.6% 0.11 67.6)
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 #3F81BA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.012
- Cool Blue #4984B8 ΔE 0.014
- Windows Blue #3778BF ΔE 0.030
- Off Blue #5684AE ΔE 0.031
- Water Blue #0E87CC ΔE 0.034
- Blue NCS #118AB2 ΔE 0.038
- Dusty Blue #5A86AD ΔE 0.038
- Nice Blue #107AB0 ΔE 0.039
Use #3F81BA 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.