#3F81CA
Closest named color: Water Blue (#0E87CC). oklch(59.5% 0.131 252.9), rgb(63, 129, 202).
Aa
Black text reads best on this color (5.20:1).
About this color
#3F81CA is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.131 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.026 away. Black text reads best on it, at 5.20:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.131) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.20:1 |
| White text | 4.03:1 |
Values
| HEX | #3F81CA |
| RGB | rgb(63, 129, 202) |
| HSL | hsl(212, 57%, 52%) |
| OKLCH | oklch(59.5% 0.131 252.9) |
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 #3F81CA | 4.03:1 | AA large text | Lc -72.8 | Content text, not long reading |
| Black text on #3F81CA | 5.20:1 | AA | Lc 36.8 | Non-text elements, placeholder text |
| #3F81CA text on white | 4.03:1 | AA large text | Lc 67.3 | Content text, not long reading |
| #3F81CA text on black | 5.20:1 | AA | Lc -34.3 | 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 500.
-
Step 50
50
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C9DBF1
oklch(88.5% 0.036 253.5)
-
Step 300
300
#A4C4EA
oklch(81% 0.064 253)
-
Step 400
400
#71A4DF
oklch(70.6% 0.103 252.8)
-
Step 500
500 (this color)
#3F81CA
oklch(59.5% 0.131 252.9)
-
Step 600
600
#2A75C3
oklch(55.6% 0.141 252.6)
-
Step 700
700
#1C62A9
oklch(49.2% 0.132 252.7)
-
Step 800
800
#1A5089
oklch(42.7% 0.11 252.9)
-
Step 900
900
#1C436D
oklch(37.7% 0.085 252.5)
-
Step 950
950
#112740
oklch(26.9% 0.055 253.1)
#3F81CA 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) | #6086CD | 0.038 |
| Deuteranopia (no green cones) | #4C79C9 | 0.023 |
| Tritanopia (no blue cones) | #00929C | 0.101 |
| Achromatopsia (no color) | #7E7E7E | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F81CA
#3F81CA
oklch(59.5% 0.131 252.9)
- #AC7000
#AC7000
oklch(59.4% 0.127 72.3)
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 #3F81CA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.026
- Windows Blue #3778BF ΔE 0.030
- Cool Blue #4984B8 ΔE 0.032
- Steel Blue #4682B4 ΔE 0.035
- Dark Sky Blue #448EE4 ΔE 0.049
- Off Blue #5684AE ΔE 0.050
- Nice Blue #107AB0 ΔE 0.054
- Blue NCS #118AB2 ΔE 0.056
Use #3F81CA 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.