#399CD9
Closest named color: Chefchaouen Blue (#4895EF). oklch(66.3% 0.128 240.1), rgb(57, 156, 217).
Aa
Black text reads best on this color (6.93:1).
About this color
#399CD9 is a medium-light, moderately saturated blue. In OKLCH its lightness is 66%, its chroma 0.128 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Chefchaouen Blue (#4895EF), ΔE 0.043 away. Black text reads best on it, at 6.93:1.
| Hue family | Blues |
| Lightness | medium-light (66%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Chefchaouen Blue (#4895EF) |
| Black text | 6.93:1 |
| White text | 3.02:1 |
Values
| HEX | #399CD9 |
| RGB | rgb(57, 156, 217) |
| HSL | hsl(203, 68%, 54%) |
| OKLCH | oklch(66.3% 0.128 240.1) |
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 #399CD9 | 3.02:1 | AA large text | Lc -62.1 | Content text, not long reading |
| Black text on #399CD9 | 6.93:1 | AA | Lc 47.3 | Large or bold text, headings |
| #399CD9 text on white | 3.02:1 | AA large text | Lc 56.7 | Large or bold text, headings |
| #399CD9 text on black | 6.93:1 | AA | Lc -45.1 | 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 500.
-
Step 50
50
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E0ECF5
oklch(93.7% 0.018 240)
-
Step 200
200
#C5DDEE
oklch(88.5% 0.035 238.7)
-
Step 300
300
#9CC7E5
oklch(80.9% 0.062 239)
-
Step 400
400
#63A9D9
oklch(70.8% 0.1 240.2)
-
Step 500
500 (this color)
#399CD9
oklch(66.3% 0.128 240.1)
-
Step 600
600
#007BB6
oklch(55.6% 0.128 240.2)
-
Step 700
700
#00679A
oklch(49.1% 0.113 240.5)
-
Step 800
800
#00547F
oklch(42.6% 0.099 240.7)
-
Step 900
900
#064669
oklch(37.6% 0.083 240.5)
-
Step 950
950
#08293D
oklch(26.9% 0.053 239.9)
#399CD9 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) | #7F9DDC | 0.066 |
| Deuteranopia (no green cones) | #6A8DD8 | 0.054 |
| Tritanopia (no blue cones) | #00ABB1 | 0.086 |
| Achromatopsia (no color) | #949494 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #399CD9
#399CD9
oklch(66.3% 0.128 240.1)
- #CB7E37
#CB7E37
oklch(66.2% 0.128 60)
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 #399CD9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Chefchaouen Blue #4895EF ΔE 0.043
- Dark Sky Blue #448EE4 ΔE 0.045
- Cornflower Blue #6495ED ΔE 0.053
- Faded Blue #658CBB ΔE 0.060
- Water Blue #0E87CC ΔE 0.066
- Soft Blue #6488EA ΔE 0.071
- Dodger Blue #1E90FF ΔE 0.072
- Cool Blue #4984B8 ΔE 0.073
Use #399CD9 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.