#397FDF
Closest named color: Dark Sky Blue (#448EE4). oklch(60.1% 0.162 257.2), rgb(57, 127, 223).
Aa
Black text reads best on this color (5.27:1).
About this color
#397FDF is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.162 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.043 away. Black text reads best on it, at 5.27:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.162) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.27:1 |
| White text | 3.98:1 |
Values
| HEX | #397FDF |
| RGB | rgb(57, 127, 223) |
| HSL | hsl(215, 72%, 55%) |
| OKLCH | oklch(60.1% 0.162 257.2) |
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 #397FDF | 3.98:1 | AA large text | Lc -72.3 | Content text, not long reading |
| Black text on #397FDF | 5.27:1 | AA | Lc 37.3 | Non-text elements, placeholder text |
| #397FDF text on white | 3.98:1 | AA large text | Lc 66.7 | Content text, not long reading |
| #397FDF text on black | 5.27:1 | AA | Lc -34.9 | 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 500.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E0EBFA
oklch(93.6% 0.024 256.1)
-
Step 200
200
#C7DBF7
oklch(88.5% 0.044 256.8)
-
Step 300
300
#A0C3F4
oklch(80.9% 0.079 256.8)
-
Step 400
400
#6CA2EF
oklch(70.7% 0.127 257.3)
-
Step 500
500 (this color)
#397FDF
oklch(60.1% 0.162 257.2)
-
Step 600
600
#2070D8
oklch(55.7% 0.177 257.2)
-
Step 700
700
#115DBB
oklch(49.1% 0.164 257.2)
-
Step 800
800
#124C97
oklch(42.6% 0.136 257.2)
-
Step 900
900
#174078
oklch(37.6% 0.106 257.3)
-
Step 950
950
#0F2646
oklch(26.9% 0.066 257.2)
#397FDF 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) | #4F88E3 | 0.033 |
| Deuteranopia (no green cones) | #3078DD | 0.021 |
| Tritanopia (no blue cones) | #0096A4 | 0.126 |
| Achromatopsia (no color) | #7F7F7F | 0.162 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #397FDF
#397FDF
oklch(60.1% 0.162 257.2)
- #AA7500
#AA7500
oklch(60.2% 0.126 77.2)
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 #397FDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.043
- Water Blue #0E87CC ΔE 0.044
- Clear Blue #247AFD ΔE 0.050
- Windows Blue #3778BF ΔE 0.050
- Soft Blue #6488EA ΔE 0.053
- Royal Blue #4169E1 ΔE 0.056
- Dodger Blue #1E90FF ΔE 0.059
- Cerulean Blue #056EEE ΔE 0.060
Use #397FDF 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.