#399BD0
Closest named color: Dark Sky Blue (#448EE4). oklch(65.6% 0.119 236.6), rgb(57, 155, 208).
Aa
Black text reads best on this color (6.77:1).
About this color
#399BD0 is a medium-light, moderately saturated blue. In OKLCH its lightness is 66%, its chroma 0.119 and its hue 237°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.052 away. Black text reads best on it, at 6.77:1.
| Hue family | Blues |
| Lightness | medium-light (66%) |
| Chroma | moderately saturated (0.119) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 6.77:1 |
| White text | 3.10:1 |
Values
| HEX | #399BD0 |
| RGB | rgb(57, 155, 208) |
| HSL | hsl(201, 62%, 52%) |
| OKLCH | oklch(65.6% 0.119 236.6) |
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 #399BD0 | 3.10:1 | AA large text | Lc -63.0 | Content text, not long reading |
| Black text on #399BD0 | 6.77:1 | AA | Lc 46.4 | Large or bold text, headings |
| #399BD0 text on white | 3.10:1 | AA large text | Lc 57.6 | Large or bold text, headings |
| #399BD0 text on black | 6.77:1 | AA | Lc -44.1 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E0ECF4
oklch(93.6% 0.017 236.7)
-
Step 200
200
#C6DDEC
oklch(88.5% 0.032 236.4)
-
Step 300
300
#9DC7E2
oklch(80.9% 0.059 236.7)
-
Step 400
400
#64AAD3
oklch(70.8% 0.093 235.8)
-
Step 500
500 (this color)
#399BD0
oklch(65.6% 0.119 236.6)
-
Step 600
600
#007CB0
oklch(55.5% 0.121 236.7)
-
Step 700
700
#006895
oklch(49% 0.107 237)
-
Step 800
800
#00557B
oklch(42.6% 0.093 237.2)
-
Step 900
900
#084765
oklch(37.7% 0.077 236.4)
-
Step 950
950
#092A3B
oklch(27.1% 0.049 235.4)
#399BD0 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) | #829AD2 | 0.070 |
| Deuteranopia (no green cones) | #6D8CCF | 0.057 |
| Tritanopia (no blue cones) | #00A9AD | 0.078 |
| Achromatopsia (no color) | #929292 | 0.119 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #399BD0
#399BD0
oklch(65.6% 0.119 236.6)
- #C77C42
#C77C42
oklch(65.5% 0.119 56.4)
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 #399BD0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.052
- Faded Blue #658CBB ΔE 0.053
- Chefchaouen Blue #4895EF ΔE 0.055
- Water Blue #0E87CC ΔE 0.063
- Cornflower Blue #6495ED ΔE 0.063
- Cool Blue #4984B8 ΔE 0.066
- Blue NCS #118AB2 ΔE 0.066
- Dusty Blue #5A86AD ΔE 0.069
Use #399BD0 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.