#3781DC
Closest named color: Water Blue (#0E87CC). oklch(60.3% 0.157 255.4), rgb(55, 129, 220).
Aa
Black text reads best on this color (5.33:1).
About this color
#3781DC is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.157 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.037 away. Black text reads best on it, at 5.33:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.157) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.33:1 |
| White text | 3.93:1 |
Values
| HEX | #3781DC |
| RGB | rgb(55, 129, 220) |
| HSL | hsl(213, 70%, 54%) |
| OKLCH | oklch(60.3% 0.157 255.4) |
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 #3781DC | 3.93:1 | AA large text | Lc -71.9 | Content text, not long reading |
| Black text on #3781DC | 5.33:1 | AA | Lc 37.7 | Non-text elements, placeholder text |
| #3781DC text on white | 3.93:1 | AA large text | Lc 66.4 | Content text, not long reading |
| #3781DC text on black | 5.33:1 | AA | Lc -35.3 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF9
oklch(93.6% 0.022 254.4)
-
Step 200
200
#C7DBF6
oklch(88.5% 0.043 255.9)
-
Step 300
300
#A0C3F2
oklch(80.8% 0.077 255.9)
-
Step 400
400
#6BA3EC
oklch(70.7% 0.123 255.5)
-
Step 500
500 (this color)
#3781DC
oklch(60.3% 0.157 255.4)
-
Step 600
600
#1A72D4
oklch(55.7% 0.17 255.2)
-
Step 700
700
#0A5EB7
oklch(49% 0.158 255.5)
-
Step 800
800
#0F4E94
oklch(42.8% 0.13 255.1)
-
Step 900
900
#164176
oklch(37.6% 0.102 255.6)
-
Step 950
950
#0E2745
oklch(27.1% 0.064 254.6)
#3781DC 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) | #5588E0 | 0.035 |
| Deuteranopia (no green cones) | #3879DA | 0.021 |
| Tritanopia (no blue cones) | #0096A4 | 0.119 |
| Achromatopsia (no color) | #808080 | 0.157 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3781DC
#3781DC
oklch(60.3% 0.157 255.4)
- #AC7400
#AC7400
oklch(60.2% 0.127 75.4)
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 #3781DC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.037
- Dark Sky Blue #448EE4 ΔE 0.039
- Windows Blue #3778BF ΔE 0.047
- Soft Blue #6488EA ΔE 0.053
- Clear Blue #247AFD ΔE 0.056
- Cool Blue #4984B8 ΔE 0.059
- Dodger Blue #1E90FF ΔE 0.060
- Chefchaouen Blue #4895EF ΔE 0.061
Use #3781DC 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.