#309CFB
Closest named color: Chefchaouen Blue (#4895EF). oklch(67.9% 0.169 249.8), rgb(48, 156, 251).
Aa
Black text reads best on this color (7.27:1).
About this color
#309CFB is a medium-light, vivid blue. In OKLCH its lightness is 68%, its chroma 0.169 and its hue 250°. Its hue sits on the cool side of the wheel. The nearest named color is Chefchaouen Blue (#4895EF), ΔE 0.025 away. Black text reads best on it, at 7.27:1.
| Hue family | Blues |
| Lightness | medium-light (68%) |
| Chroma | vivid (0.169) |
| Temperature | cool |
| Nearest name | Chefchaouen Blue (#4895EF) |
| Black text | 7.27:1 |
| White text | 2.88:1 |
Values
| HEX | #309CFB |
| RGB | rgb(48, 156, 251) |
| HSL | hsl(208, 96%, 59%) |
| OKLCH | oklch(67.9% 0.169 249.8) |
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 #309CFB | 2.88:1 | Fails | Lc -59.9 | Large or bold text, headings |
| Black text on #309CFB | 7.27:1 | AAA | Lc 49.4 | Large or bold text, headings |
| #309CFB text on white | 2.88:1 | Fails | Lc 54.6 | Large or bold text, headings |
| #309CFB text on black | 7.27:1 | AAA | Lc -47.2 | 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
#EFF6FF
oklch(97% 0.014 254.6)
-
Step 100
100
#DBECFE
oklch(93.6% 0.03 249.7)
-
Step 200
200
#BDDDFF
oklch(88.5% 0.058 250.1)
-
Step 300
300
#8EC6FF
oklch(80.9% 0.1 249.6)
-
Step 400
400 (this color)
#309CFB
oklch(67.9% 0.169 249.8)
-
Step 500
500
#008CEF
oklch(63% 0.178 249.9)
-
Step 600
600
#0076CA
oklch(55.7% 0.156 249.7)
-
Step 700
700
#0063AB
oklch(49.2% 0.138 249.7)
-
Step 800
800
#00518D
oklch(42.7% 0.12 249.5)
-
Step 900
900
#004377
oklch(37.7% 0.106 249.9)
-
Step 950
950
#00274A
oklch(26.9% 0.077 250.5)
#309CFB 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) | #6EA2FF | 0.054 |
| Deuteranopia (no green cones) | #4E90F9 | 0.033 |
| Tritanopia (no blue cones) | #00B3BF | 0.125 |
| Achromatopsia (no color) | #989898 | 0.169 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #309CFB
#309CFB
oklch(67.9% 0.169 249.8)
- #D18500
#D18500
oklch(68% 0.147 69.8)
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 #309CFB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Chefchaouen Blue #4895EF ΔE 0.025
- Dodger Blue #1E90FF ΔE 0.036
- Cornflower Blue #6495ED ΔE 0.042
- Dark Sky Blue #448EE4 ΔE 0.045
- Soft Blue #6488EA ΔE 0.061
- Water Blue #0E87CC ΔE 0.088
- Periwinkle Blue #8F99FB ΔE 0.088
- Clear Blue #247AFD ΔE 0.090
Use #309CFB 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.