#3B73BF
Closest named color: Windows Blue (#3778BF). oklch(55.5% 0.133 256.7), rgb(59, 115, 191).
Aa
White text reads best on this color (4.78:1).
About this color
#3B73BF is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.133 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.014 away. White text reads best on it, at 4.78:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.133) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.39:1 |
| White text | 4.78:1 |
Values
| HEX | #3B73BF |
| RGB | rgb(59, 115, 191) |
| HSL | hsl(215, 53%, 49%) |
| OKLCH | oklch(55.5% 0.133 256.7) |
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 #3B73BF | 4.78:1 | AA | Lc -78.3 | Fine for body text |
| Black text on #3B73BF | 4.39:1 | AA large text | Lc 31.2 | Non-text elements, placeholder text |
| #3B73BF text on white | 4.78:1 | AA | Lc 72.9 | Content text, not long reading |
| #3B73BF text on black | 4.39:1 | AA large text | Lc -28.8 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EBF6
oklch(93.7% 0.017 256.3)
-
Step 200
200
#CBDAEF
oklch(88.4% 0.033 256.8)
-
Step 300
300
#A8C3E7
oklch(80.9% 0.059 255.7)
-
Step 400
400
#7AA3DC
oklch(70.8% 0.095 256.7)
-
Step 500
500
#578BD2
oklch(63.2% 0.121 256.5)
-
Step 600
600 (this color)
#3B73BF
oklch(55.5% 0.133 256.7)
-
Step 700
700
#2D60A5
oklch(49% 0.124 256.8)
-
Step 800
800
#274F86
oklch(42.8% 0.102 256.9)
-
Step 900
900
#24426B
oklch(37.7% 0.079 256.6)
-
Step 950
950
#16273F
oklch(27.1% 0.05 257.1)
#3B73BF 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) | #5079C2 | 0.029 |
| Deuteranopia (no green cones) | #3C6DBD | 0.016 |
| Tritanopia (no blue cones) | #008590 | 0.105 |
| Achromatopsia (no color) | #727272 | 0.133 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B73BF
#3B73BF
oklch(55.5% 0.133 256.7)
- #996800
#996800
oklch(55.5% 0.116 76.4)
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 #3B73BF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.014
- French Blue #436BAD ΔE 0.032
- Mid Blue #276AB3 ΔE 0.036
- Flat Blue #3C73A8 ΔE 0.036
- Nice Blue #107AB0 ΔE 0.041
- Muted Blue #3B719F ΔE 0.050
- Steel Blue #4682B4 ΔE 0.052
- Cool Blue #4984B8 ΔE 0.055
Use #3B73BF 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.