#397BD7
Closest named color: Windows Blue (#3778BF). oklch(58.7% 0.156 257.4), rgb(57, 123, 215).
Aa
Black text reads best on this color (4.98:1).
About this color
#397BD7 is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.156 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.037 away. Black text reads best on it, at 4.98:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.156) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.98:1 |
| White text | 4.20:1 |
Values
| HEX | #397BD7 |
| RGB | rgb(57, 123, 215) |
| HSL | hsl(215, 66%, 53%) |
| OKLCH | oklch(58.7% 0.156 257.4) |
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 #397BD7 | 4.20:1 | AA large text | Lc -74.2 | Content text, not long reading |
| Black text on #397BD7 | 4.98:1 | AA | Lc 35.4 | Non-text elements, placeholder text |
| #397BD7 text on white | 4.20:1 | AA large text | Lc 68.7 | Content text, not long reading |
| #397BD7 text on black | 4.98:1 | AA | Lc -33.0 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EBF8
oklch(93.7% 0.02 257.5)
-
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
#73A2E6
oklch(70.7% 0.112 257.6)
-
Step 500
500
#4D89DF
oklch(63% 0.145 257.6)
-
Step 600
600 (this color)
#397BD7
oklch(58.7% 0.156 257.4)
-
Step 700
700
#225EB1
oklch(49% 0.146 257.6)
-
Step 800
800
#1E4E8F
oklch(42.8% 0.119 257.1)
-
Step 900
900
#1E4172
oklch(37.6% 0.093 257.3)
-
Step 950
950
#122643
oklch(26.9% 0.06 257.7)
#397BD7 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) | #4E83DB | 0.031 |
| Deuteranopia (no green cones) | #3175D5 | 0.018 |
| Tritanopia (no blue cones) | #00919E | 0.123 |
| Achromatopsia (no color) | #7B7B7B | 0.156 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #397BD7
#397BD7
oklch(58.7% 0.156 257.4)
- #A47100
#A47100
oklch(58.6% 0.123 77.4)
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 #397BD7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.037
- Water Blue #0E87CC ΔE 0.042
- Royal Blue #4169E1 ΔE 0.050
- Dark Sky Blue #448EE4 ΔE 0.055
- Cerulean Blue #056EEE ΔE 0.058
- Clear Blue #247AFD ΔE 0.058
- Cool Blue #4984B8 ΔE 0.060
- Steel Blue #4682B4 ΔE 0.062
Use #397BD7 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.