#3F9BDF
Closest named color: Chefchaouen Blue (#4895EF). oklch(66.5% 0.133 244.3), rgb(63, 155, 223).
Aa
Black text reads best on this color (6.96:1).
About this color
#3F9BDF is a medium-light, moderately saturated blue. In OKLCH its lightness is 67%, its chroma 0.133 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Chefchaouen Blue (#4895EF), ΔE 0.033 away. Black text reads best on it, at 6.96:1.
| Hue family | Blues |
| Lightness | medium-light (67%) |
| Chroma | moderately saturated (0.133) |
| Temperature | cool |
| Nearest name | Chefchaouen Blue (#4895EF) |
| Black text | 6.96:1 |
| White text | 3.01:1 |
Values
| HEX | #3F9BDF |
| RGB | rgb(63, 155, 223) |
| HSL | hsl(206, 71%, 56%) |
| OKLCH | oklch(66.5% 0.133 244.3) |
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 #3F9BDF | 3.01:1 | AA large text | Lc -61.9 | Content text, not long reading |
| Black text on #3F9BDF | 6.96:1 | AA | Lc 47.5 | Large or bold text, headings |
| #3F9BDF text on white | 3.01:1 | AA large text | Lc 56.5 | Large or bold text, headings |
| #3F9BDF text on black | 6.96:1 | AA | Lc -45.2 | 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 500.
-
Step 50
50
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E0ECF6
oklch(93.7% 0.019 243)
-
Step 200
200
#C6DCF0
oklch(88.4% 0.036 245.7)
-
Step 300
300
#9DC6E8
oklch(80.9% 0.065 243.7)
-
Step 400
400
#65A7DD
oklch(70.6% 0.104 244.7)
-
Step 500
500 (this color)
#3F9BDF
oklch(66.5% 0.133 244.3)
-
Step 600
600
#0079BD
oklch(55.5% 0.138 244.2)
-
Step 700
700
#0066A0
oklch(49.2% 0.121 244)
-
Step 800
800
#005384
oklch(42.6% 0.106 244.3)
-
Step 900
900
#0B456C
oklch(37.7% 0.087 244.5)
-
Step 950
950
#0A293F
oklch(27.1% 0.054 243.5)
#3F9BDF 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) | #7C9DE2 | 0.059 |
| Deuteranopia (no green cones) | #668EDE | 0.045 |
| Tritanopia (no blue cones) | #00ACB3 | 0.096 |
| Achromatopsia (no color) | #949494 | 0.133 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F9BDF
#3F9BDF
oklch(66.5% 0.133 244.3)
- #CB802B
#CB802B
oklch(66.5% 0.133 64.4)
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 #3F9BDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Chefchaouen Blue #4895EF ΔE 0.033
- Dark Sky Blue #448EE4 ΔE 0.038
- Cornflower Blue #6495ED ΔE 0.043
- Soft Blue #6488EA ΔE 0.062
- Faded Blue #658CBB ΔE 0.063
- Dodger Blue #1E90FF ΔE 0.064
- Water Blue #0E87CC ΔE 0.067
- Cool Blue #4984B8 ΔE 0.076
Use #3F9BDF 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.