#3B66BF
Closest named color: Mid Blue (#276AB3). oklch(52.7% 0.148 262.9), rgb(59, 102, 191).
Aa
White text reads best on this color (5.47:1).
About this color
#3B66BF is a medium-dark, vivid blue. In OKLCH its lightness is 53%, its chroma 0.148 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.028 away. White text reads best on it, at 5.47:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | vivid (0.148) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.83:1 |
| White text | 5.47:1 |
Values
| HEX | #3B66BF |
| RGB | rgb(59, 102, 191) |
| HSL | hsl(220, 53%, 49%) |
| OKLCH | oklch(52.7% 0.148 262.9) |
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 #3B66BF | 5.47:1 | AA | Lc -82.3 | Fine for body text |
| Black text on #3B66BF | 3.83:1 | AA large text | Lc 27.1 | Dividers and decoration only |
| #3B66BF text on white | 5.47:1 | AA | Lc 77.0 | Fine for body text |
| #3B66BF text on black | 3.83:1 | AA large text | Lc -24.8 | Dividers and decoration only |
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 600.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CCDAF2
oklch(88.5% 0.036 261.3)
-
Step 300
300
#AAC1EC
oklch(80.8% 0.066 262.8)
-
Step 400
400
#7DA0E3
oklch(70.7% 0.106 262.8)
-
Step 500
500
#5D87DB
oklch(63.1% 0.135 263)
-
Step 600
600 (this color)
#3B66BF
oklch(52.7% 0.148 262.9)
-
Step 700
700
#355CAE
oklch(49.1% 0.138 263.1)
-
Step 800
800
#2C4C8D
oklch(42.8% 0.114 262.8)
-
Step 900
900
#284070
oklch(37.8% 0.088 262.8)
-
Step 950
950
#172642
oklch(27.1% 0.056 262)
#3B66BF 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) | #3870C2 | 0.026 |
| Deuteranopia (no green cones) | #1C64BD | 0.025 |
| Tritanopia (no blue cones) | #007B89 | 0.120 |
| Achromatopsia (no color) | #696969 | 0.148 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B66BF
#3B66BF
oklch(52.7% 0.148 262.9)
- #896400
#896400
oklch(52.7% 0.108 83.1)
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 #3B66BF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.028
- French Blue #436BAD ΔE 0.035
- Windows Blue #3778BF ΔE 0.049
- Royal Blue #4169E1 ΔE 0.053
- Flat Blue #3C73A8 ΔE 0.056
- Iris #6258C4 ΔE 0.057
- Warm Blue #4B57DB ΔE 0.060
- Dark Periwinkle #665FD1 ΔE 0.063
Use #3B66BF 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.