#309FDF
Closest named color: Chefchaouen Blue (#4895EF). oklch(67% 0.135 239.4), rgb(48, 159, 223).
Aa
Black text reads best on this color (7.15:1).
About this color
#309FDF is a medium-light, moderately saturated blue. In OKLCH its lightness is 67%, its chroma 0.135 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Chefchaouen Blue (#4895EF), ΔE 0.042 away. Black text reads best on it, at 7.15:1.
| Hue family | Blues |
| Lightness | medium-light (67%) |
| Chroma | moderately saturated (0.135) |
| Temperature | cool |
| Nearest name | Chefchaouen Blue (#4895EF) |
| Black text | 7.15:1 |
| White text | 2.93:1 |
Values
| HEX | #309FDF |
| RGB | rgb(48, 159, 223) |
| HSL | hsl(202, 73%, 53%) |
| OKLCH | oklch(67% 0.135 239.4) |
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 #309FDF | 2.93:1 | Fails | Lc -60.7 | Content text, not long reading |
| Black text on #309FDF | 7.15:1 | AAA | Lc 48.6 | Large or bold text, headings |
| #309FDF text on white | 2.93:1 | Fails | Lc 55.4 | Large or bold text, headings |
| #309FDF 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
#EFF7FC
oklch(97.2% 0.011 234.8)
-
Step 100
100
#DCEDF9
oklch(93.7% 0.024 238.4)
-
Step 200
200
#BEDEF5
oklch(88.5% 0.046 239.3)
-
Step 300
300
#8DC9F2
oklch(81% 0.085 239)
-
Step 400
400 (this color)
#309FDF
oklch(67% 0.135 239.4)
-
Step 500
500
#0093D6
oklch(63.1% 0.143 239.3)
-
Step 600
600
#007BB5
oklch(55.6% 0.127 239.8)
-
Step 700
700
#006899
oklch(49.2% 0.111 239.3)
-
Step 800
800
#00557E
oklch(42.8% 0.097 239.2)
-
Step 900
900
#00466A
oklch(37.6% 0.086 240.1)
-
Step 950
950
#002A41
oklch(27.1% 0.061 239)
#309FDF 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) | #81A0E2 | 0.072 |
| Deuteranopia (no green cones) | #698FDE | 0.057 |
| Tritanopia (no blue cones) | #00AFB5 | 0.090 |
| Achromatopsia (no color) | #979797 | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #309FDF
#309FDF
oklch(67% 0.135 239.4)
- #D17F32
#D17F32
oklch(67.1% 0.135 59.8)
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 #309FDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Chefchaouen Blue #4895EF ΔE 0.042
- Dark Sky Blue #448EE4 ΔE 0.049
- Cornflower Blue #6495ED ΔE 0.053
- Dodger Blue #1E90FF ΔE 0.070
- Faded Blue #658CBB ΔE 0.070
- Water Blue #0E87CC ΔE 0.073
- Turquoise Blue #06B1C4 ΔE 0.074
- Soft Blue #6488EA ΔE 0.074
Use #309FDF 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.