#3B66B3
Closest named color: Mid Blue (#276AB3). oklch(51.9% 0.131 261.1), rgb(59, 102, 179).
Aa
White text reads best on this color (5.61:1).
About this color
#3B66B3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 52%, its chroma 0.131 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Mid Blue (#276AB3), ΔE 0.018 away. White text reads best on it, at 5.61:1.
| Hue family | Blues |
| Lightness | medium-dark (52%) |
| Chroma | moderately saturated (0.131) |
| Temperature | cool |
| Nearest name | Mid Blue (#276AB3) |
| Black text | 3.73:1 |
| White text | 5.61:1 |
Values
| HEX | #3B66B3 |
| RGB | rgb(59, 102, 179) |
| HSL | hsl(218, 50%, 47%) |
| OKLCH | oklch(51.9% 0.131 261.1) |
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 #3B66B3 | 5.61:1 | AA | Lc -83.1 | Fine for body text |
| Black text on #3B66B3 | 3.73:1 | AA large text | Lc 26.2 | Dividers and decoration only |
| #3B66B3 text on white | 5.61:1 | AA | Lc 77.8 | Fine for body text |
| #3B66B3 text on black | 3.73:1 | AA large text | Lc -24.0 | 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 700.
-
Step 50
50
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CCDAF1
oklch(88.5% 0.035 260.4)
-
Step 300
300
#AAC2EA
oklch(81% 0.063 260.6)
-
Step 400
400
#7DA1E0
oklch(70.7% 0.101 261.2)
-
Step 500
500
#5B88D7
oklch(63% 0.13 261)
-
Step 600
600
#4170C5
oklch(55.5% 0.142 261.2)
-
Step 700
700 (this color)
#3B66B3
oklch(51.9% 0.131 261.1)
-
Step 800
800
#2B4D8A
oklch(42.7% 0.109 261.1)
-
Step 900
900
#27416E
oklch(37.8% 0.084 260.7)
-
Step 950
950
#172640
oklch(27% 0.053 260.8)
#3B66B3 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) | #426DB6 | 0.022 |
| Deuteranopia (no green cones) | #2E62B1 | 0.018 |
| Tritanopia (no blue cones) | #007884 | 0.107 |
| Achromatopsia (no color) | #676767 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B66B3
#3B66B3
oklch(51.9% 0.131 261.1)
- #886100
#886100
oklch(52% 0.107 81.1)
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 #3B66B3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Mid Blue #276AB3 ΔE 0.018
- French Blue #436BAD ΔE 0.021
- Flat Blue #3C73A8 ΔE 0.044
- Muted Blue #3B719F ΔE 0.049
- Dusky Blue #475F94 ΔE 0.050
- Windows Blue #3778BF ΔE 0.050
- Denim Blue #3B5B92 ΔE 0.057
- Nice Blue #107AB0 ΔE 0.059
Use #3B66B3 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.