#4370BB
Closest named color: Windows Blue (#3778BF). oklch(55% 0.128 260.1), rgb(67, 112, 187).
Aa
White text reads best on this color (4.91:1).
About this color
#4370BB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.128 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.022 away. White text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.27:1 |
| White text | 4.91:1 |
Values
| HEX | #4370BB |
| RGB | rgb(67, 112, 187) |
| HSL | hsl(218, 47%, 50%) |
| OKLCH | oklch(55% 0.128 260.1) |
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 #4370BB | 4.91:1 | AA | Lc -79.2 | Fine for body text |
| Black text on #4370BB | 4.27:1 | AA large text | Lc 30.3 | Non-text elements, placeholder text |
| #4370BB text on white | 4.91:1 | AA | Lc 73.8 | Content text, not long reading |
| #4370BB text on black | 4.27:1 | AA large text | Lc -27.9 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF5
oklch(93.5% 0.017 259.4)
-
Step 200
200
#CDDAEF
oklch(88.5% 0.032 260)
-
Step 300
300
#ABC2E6
oklch(80.9% 0.057 259.3)
-
Step 400
400
#7FA2DA
oklch(70.8% 0.091 259.6)
-
Step 500
500
#5F89D0
oklch(63.1% 0.117 260.4)
-
Step 600
600 (this color)
#4370BB
oklch(55% 0.128 260.1)
-
Step 700
700
#365FA3
oklch(49% 0.119 260)
-
Step 800
800
#2D4E84
oklch(42.7% 0.098 259.8)
-
Step 900
900
#29416A
oklch(37.7% 0.077 260.5)
-
Step 950
950
#18263E
oklch(26.9% 0.049 260.7)
#4370BB 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) | #4F77BE | 0.025 |
| Deuteranopia (no green cones) | #3D6BB9 | 0.016 |
| Tritanopia (no blue cones) | #00818C | 0.106 |
| Achromatopsia (no color) | #717171 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4370BB
#4370BB
oklch(55% 0.128 260.1)
- #946900
#946900
oklch(55.1% 0.114 80.3)
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 #4370BB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.022
- French Blue #436BAD ΔE 0.024
- Mid Blue #276AB3 ΔE 0.034
- Flat Blue #3C73A8 ΔE 0.034
- Nice Blue #107AB0 ΔE 0.046
- Muted Blue #3B719F ΔE 0.047
- Dull Blue #49759C ΔE 0.055
- Steel Blue #4682B4 ΔE 0.055
Use #4370BB 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.