#4378AE
Closest named color: Flat Blue (#3C73A8). oklch(56% 0.102 250.5), rgb(67, 120, 174).
Aa
White text reads best on this color (4.62:1).
About this color
#4378AE is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.102 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Flat Blue (#3C73A8), ΔE 0.018 away. White text reads best on it, at 4.62:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Flat Blue (#3C73A8) |
| Black text | 4.53:1 |
| White text | 4.62:1 |
Values
| HEX | #4378AE |
| RGB | rgb(67, 120, 174) |
| HSL | hsl(210, 44%, 47%) |
| OKLCH | oklch(56% 0.102 250.5) |
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 #4378AE | 4.62:1 | AA | Lc -77.4 | Fine for body text |
| Black text on #4378AE | 4.53:1 | AA | Lc 32.1 | Non-text elements, placeholder text |
| #4378AE text on white | 4.62:1 | AA | Lc 72.0 | Content text, not long reading |
| #4378AE text on black | 4.53:1 | AA | Lc -29.7 | 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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E3EBF3
oklch(93.6% 0.014 248)
-
Step 200
200
#CDDBEA
oklch(88.5% 0.026 250)
-
Step 300
300
#ABC3DE
oklch(80.8% 0.046 251.5)
-
Step 400
400
#7EA4CD
oklch(70.6% 0.073 250.8)
-
Step 500
500
#5D8DC0
oklch(63% 0.093 250.9)
-
Step 600
600 (this color)
#4378AE
oklch(56% 0.102 250.5)
-
Step 700
700
#336494
oklch(49.2% 0.094 249.9)
-
Step 800
800
#2B5178
oklch(42.6% 0.078 250.7)
-
Step 900
900
#274461
oklch(37.8% 0.061 249.7)
-
Step 950
950
#172839
oklch(27.1% 0.039 249.5)
#4378AE 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) | #617AB0 | 0.035 |
| Deuteranopia (no green cones) | #5370AD | 0.026 |
| Tritanopia (no blue cones) | #00858B | 0.084 |
| Achromatopsia (no color) | #757575 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #4378AE
#4378AE
oklch(56% 0.102 250.5)
- #9A6927
#9A6927
oklch(56% 0.102 70.6)
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 #4378AE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Flat Blue #3C73A8 ΔE 0.018
- Dull Blue #49759C ΔE 0.028
- Windows Blue #3778BF ΔE 0.028
- Steel Blue #4682B4 ΔE 0.029
- Nice Blue #107AB0 ΔE 0.030
- Muted Blue #3B719F ΔE 0.030
- Cerulean #457B9D ΔE 0.031
- Stormy Blue #507B9C ΔE 0.034
Use #4378AE 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.