#397FC7
Closest named color: Windows Blue (#3778BF). oklch(58.6% 0.131 251.6), rgb(57, 127, 199).
Aa
Black text reads best on this color (5.03:1).
About this color
#397FC7 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.131 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.022 away. Black text reads best on it, at 5.03:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.131) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.03:1 |
| White text | 4.17:1 |
Values
| HEX | #397FC7 |
| RGB | rgb(57, 127, 199) |
| HSL | hsl(210, 56%, 50%) |
| OKLCH | oklch(58.6% 0.131 251.6) |
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 #397FC7 | 4.17:1 | AA large text | Lc -73.9 | Content text, not long reading |
| Black text on #397FC7 | 5.03:1 | AA | Lc 35.7 | Non-text elements, placeholder text |
| #397FC7 text on white | 4.17:1 | AA large text | Lc 68.4 | Content text, not long reading |
| #397FC7 text on black | 5.03:1 | AA | Lc -33.2 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF5
oklch(93.6% 0.017 250.8)
-
Step 200
200
#CADBEF
oklch(88.5% 0.033 252.5)
-
Step 300
300
#A5C4E6
oklch(80.9% 0.059 250.9)
-
Step 400
400
#74A5DA
oklch(70.8% 0.094 251.1)
-
Step 500
500
#4E8DD0
oklch(63.1% 0.121 251.6)
-
Step 600
600 (this color)
#397FC7
oklch(58.6% 0.131 251.6)
-
Step 700
700
#2163A3
oklch(49.2% 0.122 251.3)
-
Step 800
800
#1E5184
oklch(42.8% 0.101 251.4)
-
Step 900
900
#1E436A
oklch(37.6% 0.079 251.8)
-
Step 950
950
#13283E
oklch(27.1% 0.049 251.1)
#397FC7 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) | #5E83CA | 0.039 |
| Deuteranopia (no green cones) | #4976C6 | 0.026 |
| Tritanopia (no blue cones) | #009099 | 0.101 |
| Achromatopsia (no color) | #7C7C7C | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #397FC7
#397FC7
oklch(58.6% 0.131 251.6)
- #AA6D00
#AA6D00
oklch(58.6% 0.126 71.1)
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 #397FC7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.022
- Water Blue #0E87CC ΔE 0.026
- Cool Blue #4984B8 ΔE 0.033
- Steel Blue #4682B4 ΔE 0.034
- Nice Blue #107AB0 ΔE 0.045
- Off Blue #5684AE ΔE 0.051
- Flat Blue #3C73A8 ΔE 0.053
- Blue NCS #118AB2 ΔE 0.054
Use #397FC7 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.