#3778C4
Closest named color: Windows Blue (#3778BF). oklch(56.8% 0.135 254.2), rgb(55, 120, 196).
Aa
Black text reads best on this color (4.64:1).
About this color
#3778C4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.135 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.008 away. Black text reads best on it, at 4.64:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.135) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.64:1 |
| White text | 4.51:1 |
Values
| HEX | #3778C4 |
| RGB | rgb(55, 120, 196) |
| HSL | hsl(212, 56%, 49%) |
| OKLCH | oklch(56.8% 0.135 254.2) |
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 #3778C4 | 4.51:1 | AA | Lc -76.5 | Fine for body text |
| Black text on #3778C4 | 4.64:1 | AA | Lc 33.0 | Non-text elements, placeholder text |
| #3778C4 text on white | 4.51:1 | AA | Lc 71.1 | Content text, not long reading |
| #3778C4 text on black | 4.64:1 | AA | Lc -30.6 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF6
oklch(93.7% 0.018 253.3)
-
Step 200
200
#CADBF0
oklch(88.5% 0.034 253.7)
-
Step 300
300
#A6C3E8
oklch(80.8% 0.061 254.7)
-
Step 400
400
#76A4DC
oklch(70.8% 0.096 253.9)
-
Step 500
500
#518CD3
oklch(63.2% 0.124 254.1)
-
Step 600
600 (this color)
#3778C4
oklch(56.8% 0.135 254.2)
-
Step 700
700
#2561A6
oklch(49% 0.127 254.3)
-
Step 800
800
#215086
oklch(42.8% 0.103 253.9)
-
Step 900
900
#20436C
oklch(37.8% 0.081 253.8)
-
Step 950
950
#14273F
oklch(27% 0.052 255)
#3778C4 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) | #557DC7 | 0.034 |
| Deuteranopia (no green cones) | #3F70C2 | 0.021 |
| Tritanopia (no blue cones) | #008A94 | 0.105 |
| Achromatopsia (no color) | #767676 | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3778C4
#3778C4
oklch(56.8% 0.135 254.2)
- #A06A00
#A06A00
oklch(56.8% 0.12 74.1)
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 #3778C4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.008
- Nice Blue #107AB0 ΔE 0.040
- Water Blue #0E87CC ΔE 0.041
- Flat Blue #3C73A8 ΔE 0.043
- Steel Blue #4682B4 ΔE 0.045
- French Blue #436BAD ΔE 0.045
- Cool Blue #4984B8 ΔE 0.047
- Mid Blue #276AB3 ΔE 0.048
Use #3778C4 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.