#399BF3
Closest named color: Chefchaouen Blue (#4895EF). oklch(67.4% 0.158 249.5), rgb(57, 155, 243).
Aa
Black text reads best on this color (7.15:1).
About this color
#399BF3 is a medium-light, vivid blue. In OKLCH its lightness is 67%, its chroma 0.158 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Chefchaouen Blue (#4895EF), ΔE 0.017 away. Black text reads best on it, at 7.15:1.
| Hue family | Blues |
| Lightness | medium-light (67%) |
| Chroma | vivid (0.158) |
| Temperature | cool |
| Nearest name | Chefchaouen Blue (#4895EF) |
| Black text | 7.15:1 |
| White text | 2.93:1 |
Values
| HEX | #399BF3 |
| RGB | rgb(57, 155, 243) |
| HSL | hsl(208, 89%, 59%) |
| OKLCH | oklch(67.4% 0.158 249.5) |
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 #399BF3 | 2.93:1 | Fails | Lc -60.7 | Content text, not long reading |
| Black text on #399BF3 | 7.15:1 | AAA | Lc 48.7 | Large or bold text, headings |
| #399BF3 text on white | 2.93:1 | Fails | Lc 55.4 | Large or bold text, headings |
| #399BF3 text on black | 7.15:1 | AAA | Lc -46.4 | Large or bold text, headings |
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 400.
-
Step 50
50
#EFF6FE
oklch(97% 0.013 251.6)
-
Step 100
100
#DCECFD
oklch(93.6% 0.029 249.8)
-
Step 200
200
#BEDDFD
oklch(88.5% 0.055 249.3)
-
Step 300
300
#8EC6FE
oklch(80.9% 0.099 249.1)
-
Step 400
400 (this color)
#399BF3
oklch(67.4% 0.158 249.5)
-
Step 500
500
#008DEE
oklch(63.2% 0.176 249.3)
-
Step 600
600
#0076C9
oklch(55.6% 0.155 249.4)
-
Step 700
700
#0063AA
oklch(49.1% 0.137 249.4)
-
Step 800
800
#00518D
oklch(42.7% 0.12 249.5)
-
Step 900
900
#004376
oklch(37.6% 0.105 249.5)
-
Step 950
950
#002749
oklch(26.8% 0.076 249.9)
#399BF3 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) | #72A0F7 | 0.053 |
| Deuteranopia (no green cones) | #568FF1 | 0.035 |
| Tritanopia (no blue cones) | #00B0BB | 0.117 |
| Achromatopsia (no color) | #979797 | 0.158 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #399BF3
#399BF3
oklch(67.4% 0.158 249.5)
- #CF8300
#CF8300
oklch(67.4% 0.146 69.4)
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 #399BF3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Chefchaouen Blue #4895EF ΔE 0.017
- Cornflower Blue #6495ED ΔE 0.035
- Dark Sky Blue #448EE4 ΔE 0.037
- Dodger Blue #1E90FF ΔE 0.040
- Soft Blue #6488EA ΔE 0.055
- Water Blue #0E87CC ΔE 0.080
- Periwinkle Blue #8F99FB ΔE 0.086
- Faded Blue #658CBB ΔE 0.087
Use #399BF3 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.