#3578BA
Closest named color: Windows Blue (#3778BF). oklch(56.1% 0.123 250.7), rgb(53, 120, 186).
Aa
White text reads best on this color (4.61:1).
About this color
#3578BA is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.123 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.008 away. White text reads best on it, at 4.61:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.54:1 |
| White text | 4.61:1 |
Values
| HEX | #3578BA |
| RGB | rgb(53, 120, 186) |
| HSL | hsl(210, 56%, 47%) |
| OKLCH | oklch(56.1% 0.123 250.7) |
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 #3578BA | 4.61:1 | AA | Lc -77.2 | Fine for body text |
| Black text on #3578BA | 4.54:1 | AA | Lc 32.3 | Non-text elements, placeholder text |
| #3578BA text on white | 4.61:1 | AA | Lc 71.8 | Content text, not long reading |
| #3578BA text on black | 4.54:1 | AA | Lc -29.9 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF4
oklch(93.6% 0.016 248)
-
Step 200
200
#CBDBED
oklch(88.5% 0.03 251.3)
-
Step 300
300
#A7C4E4
oklch(81% 0.055 251.1)
-
Step 400
400
#76A5D6
oklch(70.7% 0.088 250.2)
-
Step 500
500
#518DCB
oklch(63% 0.113 250.8)
-
Step 600
600 (this color)
#3578BA
oklch(56.1% 0.123 250.7)
-
Step 700
700
#25639F
oklch(49.1% 0.115 250.8)
-
Step 800
800
#215181
oklch(42.7% 0.095 251.1)
-
Step 900
900
#204467
oklch(37.8% 0.073 249.8)
-
Step 950
950
#14283C
oklch(27.1% 0.046 249.9)
#3578BA 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) | #5A7CBD | 0.040 |
| Deuteranopia (no green cones) | #476FB9 | 0.027 |
| Tritanopia (no blue cones) | #008890 | 0.094 |
| Achromatopsia (no color) | #757575 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3578BA
#3578BA
oklch(56.1% 0.123 250.7)
- #A16600
#A16600
oklch(56.1% 0.121 70.3)
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 #3578BA, 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 0.027
- Flat Blue #3C73A8 ΔE 0.029
- Steel Blue #4682B4 ΔE 0.037
- French Blue #436BAD ΔE 0.038
- Cool Blue #4984B8 ΔE 0.042
- Muted Blue #3B719F ΔE 0.043
- Mid Blue #276AB3 ΔE 0.043
Use #3578BA 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.