#0377CB
Closest named color: Windows Blue (#3778BF). oklch(56% 0.156 249.7), rgb(3, 119, 203).
Aa
White text reads best on this color (4.66:1).
About this color
#0377CB is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.156 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.029 away. White text reads best on it, at 4.66:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.156) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.50:1 |
| White text | 4.66:1 |
Values
| HEX | #0377CB |
| RGB | rgb(3, 119, 203) |
| HSL | hsl(205, 97%, 40%) |
| OKLCH | oklch(56% 0.156 249.7) |
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 #0377CB | 4.66:1 | AA | Lc -77.1 | Fine for body text |
| Black text on #0377CB | 4.50:1 | AA | Lc 32.4 | Non-text elements, placeholder text |
| #0377CB text on white | 4.66:1 | AA | Lc 71.7 | Content text, not long reading |
| #0377CB text on black | 4.50:1 | AA | Lc -30.0 | Dividers and decoration only |
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
#E0EBF7
oklch(93.5% 0.02 250.4)
-
Step 200
200
#C6DCF3
oklch(88.5% 0.04 249.5)
-
Step 300
300
#9EC5ED
oklch(80.9% 0.071 249.4)
-
Step 400
400
#67A6E4
oklch(70.8% 0.112 249.3)
-
Step 500
500
#388EDC
oklch(63.2% 0.143 249.4)
-
Step 600
600 (this color)
#0377CB
oklch(56% 0.156 249.7)
-
Step 700
700
#0063AB
oklch(49.2% 0.138 249.7)
-
Step 800
800
#00518D
oklch(42.7% 0.12 249.5)
-
Step 900
900
#104471
oklch(37.8% 0.093 249.5)
-
Step 950
950
#0C2842
oklch(27.1% 0.059 249.5)
#0377CB 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) | #4C7DCE | 0.048 |
| Deuteranopia (no green cones) | #2A6DC9 | 0.027 |
| Tritanopia (no blue cones) | #008B97 | 0.112 |
| Achromatopsia (no color) | #747474 | 0.156 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #0377CB
#0377CB
oklch(56% 0.156 249.7)
- #A16500
#A16500
oklch(55.9% 0.122 69.5)
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 #0377CB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.029
- Nice Blue #107AB0 ΔE 0.045
- Water Blue #0E87CC ΔE 0.046
- Mid Blue #276AB3 ΔE 0.047
- French Blue #436BAD ΔE 0.057
- Flat Blue #3C73A8 ΔE 0.057
- Royal Blue #4169E1 ΔE 0.059
- Cerulean Blue #056EEE ΔE 0.061
Use #0377CB 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.