#397DD8
Closest named color: Windows Blue (#3778BF). oklch(59.2% 0.155 256.7), rgb(57, 125, 216).
Aa
Black text reads best on this color (5.09:1).
About this color
#397DD8 is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.155 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.039 away. Black text reads best on it, at 5.09:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.155) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.09:1 |
| White text | 4.11:1 |
Values
| HEX | #397DD8 |
| RGB | rgb(57, 125, 216) |
| HSL | hsl(214, 67%, 54%) |
| OKLCH | oklch(59.2% 0.155 256.7) |
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 #397DD8 | 4.11:1 | AA large text | Lc -73.4 | Content text, not long reading |
| Black text on #397DD8 | 5.09:1 | AA | Lc 36.2 | Non-text elements, placeholder text |
| #397DD8 text on white | 4.11:1 | AA large text | Lc 67.9 | Content text, not long reading |
| #397DD8 text on black | 5.09:1 | AA | Lc -33.7 | Non-text elements, placeholder text |
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
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C9DBF3
oklch(88.5% 0.038 255.6)
-
Step 300
300
#A4C3EE
oklch(80.9% 0.07 256.6)
-
Step 400
400
#72A3E6
oklch(70.8% 0.112 256.4)
-
Step 500
500
#4C8ADE
oklch(63.1% 0.143 256.6)
-
Step 600
600 (this color)
#397DD8
oklch(59.2% 0.155 256.7)
-
Step 700
700
#205FB0
oklch(49.1% 0.144 256.6)
-
Step 800
800
#1D4E8F
oklch(42.8% 0.12 256.8)
-
Step 900
900
#1D4172
oklch(37.6% 0.094 256.9)
-
Step 950
950
#122743
oklch(27.1% 0.059 256.2)
#397DD8 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) | #5185DC | 0.033 |
| Deuteranopia (no green cones) | #3576D6 | 0.020 |
| Tritanopia (no blue cones) | #0092A0 | 0.120 |
| Achromatopsia (no color) | #7D7D7D | 0.155 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #397DD8
#397DD8
oklch(59.2% 0.155 256.7)
- #A77200
#A77200
oklch(59.2% 0.124 76.5)
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 #397DD8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.039
- Water Blue #0E87CC ΔE 0.039
- Dark Sky Blue #448EE4 ΔE 0.049
- Royal Blue #4169E1 ΔE 0.054
- Clear Blue #247AFD ΔE 0.058
- Cool Blue #4984B8 ΔE 0.058
- Soft Blue #6488EA ΔE 0.060
- Steel Blue #4682B4 ΔE 0.061
Use #397DD8 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.