#397FFB
Closest named color: Clear Blue (#247AFD). oklch(62% 0.198 260.8), rgb(57, 127, 251).
Aa
Black text reads best on this color (5.60:1).
About this color
#397FFB is a medium-dark, vivid blue. In OKLCH its lightness is 62%, its chroma 0.198 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Clear Blue (#247AFD), ΔE 0.020 away. Black text reads best on it, at 5.60:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | vivid (0.198) |
| Temperature | cool |
| Nearest name | Clear Blue (#247AFD) |
| Black text | 5.60:1 |
| White text | 3.74:1 |
Values
| HEX | #397FFB |
| RGB | rgb(57, 127, 251) |
| HSL | hsl(218, 96%, 60%) |
| OKLCH | oklch(62% 0.198 260.8) |
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 #397FFB | 3.74:1 | AA large text | Lc -70.0 | Content text, not long reading |
| Black text on #397FFB | 5.60:1 | AA | Lc 39.6 | Non-text elements, placeholder text |
| #397FFB text on white | 3.74:1 | AA large text | Lc 64.5 | Content text, not long reading |
| #397FFB text on black | 5.60:1 | AA | Lc -37.1 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#DFEBFD
oklch(93.6% 0.028 258.4)
-
Step 200
200
#C5DAFE
oklch(88.4% 0.055 261.2)
-
Step 300
300
#9DC2FF
oklch(81% 0.096 260.2)
-
Step 400
400
#689FFF
oklch(70.7% 0.153 260.8)
-
Step 500
500 (this color)
#397FFB
oklch(62% 0.198 260.8)
-
Step 600
600
#1968EE
oklch(55.6% 0.215 260.8)
-
Step 700
700
#0B55CF
oklch(49% 0.2 260.9)
-
Step 800
800
#0E47A8
oklch(42.8% 0.166 260.8)
-
Step 900
900
#143D85
oklch(37.8% 0.129 260.8)
-
Step 950
950
#0D244E
oklch(27% 0.083 261.2)
#397FFB 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) | #328DFF | 0.035 |
| Deuteranopia (no green cones) | #007CF9 | 0.026 |
| Tritanopia (no blue cones) | #009DB1 | 0.155 |
| Achromatopsia (no color) | #848484 | 0.199 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #397FFB
#397FFB
oklch(62% 0.198 260.8)
- #AD7C00
#AD7C00
oklch(61.9% 0.128 80.8)
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 #397FFB, closest first.
No curated palette has a color within ΔE 0.04 of #397FFB.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Clear Blue #247AFD ΔE 0.020
- Dodger Blue #1E90FF ΔE 0.042
- Cornflower #6A79F7 ΔE 0.048
- Cerulean Blue #056EEE ΔE 0.056
- Soft Blue #6488EA ΔE 0.056
- Dark Sky Blue #448EE4 ΔE 0.057
- Royal Blue #4169E1 ΔE 0.064
- Chefchaouen Blue #4895EF ΔE 0.065
Use #397FFB 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.