#0378D6
Closest named color: Windows Blue (#3778BF). oklch(56.9% 0.169 251.9), rgb(3, 120, 214).
Aa
Black text reads best on this color (4.66:1).
About this color
#0378D6 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.169 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.040 away. Black text reads best on it, at 4.66:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.169) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.66:1 |
| White text | 4.50:1 |
Values
| HEX | #0378D6 |
| RGB | rgb(3, 120, 214) |
| HSL | hsl(207, 97%, 43%) |
| OKLCH | oklch(56.9% 0.169 251.9) |
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 #0378D6 | 4.50:1 | AA | Lc -76.0 | Fine for body text |
| Black text on #0378D6 | 4.66:1 | AA | Lc 33.5 | Non-text elements, placeholder text |
| #0378D6 text on white | 4.50:1 | AA | Lc 70.5 | Content text, not long reading |
| #0378D6 text on black | 4.66:1 | AA | Lc -31.1 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF9
oklch(93.6% 0.022 254.4)
-
Step 200
200
#C6DCF5
oklch(88.6% 0.042 251.7)
-
Step 300
300
#9DC4F1
oklch(80.8% 0.076 252.3)
-
Step 400
400
#65A5EA
oklch(70.8% 0.121 251.5)
-
Step 500
500
#358CE3
oklch(63.1% 0.155 251.7)
-
Step 600
600 (this color)
#0378D6
oklch(56.9% 0.169 251.9)
-
Step 700
700
#0061B0
oklch(49% 0.147 252)
-
Step 800
800
#004F92
oklch(42.6% 0.129 252.3)
-
Step 900
900
#0E4375
oklch(37.8% 0.101 251.6)
-
Step 950
950
#0B2745
oklch(26.9% 0.065 252.8)
#0378D6 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) | #4580DA | 0.044 |
| Deuteranopia (no green cones) | #176FD4 | 0.023 |
| Tritanopia (no blue cones) | #008F9C | 0.124 |
| Achromatopsia (no color) | #777777 | 0.169 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0378D6
#0378D6
oklch(56.9% 0.169 251.9)
- #A36900
#A36900
oklch(56.9% 0.122 71.6)
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 #0378D6, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.040
- Cerulean Blue #056EEE ΔE 0.047
- Water Blue #0E87CC ΔE 0.047
- Royal Blue #4169E1 ΔE 0.050
- Mid Blue #276AB3 ΔE 0.061
- Nice Blue #107AB0 ΔE 0.061
- Clear Blue #247AFD ΔE 0.061
- French Blue #436BAD ΔE 0.070
Use #0378D6 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.