#3B66D5
Closest named color: Royal Blue (#4169E1). oklch(54.2% 0.178 265), rgb(59, 102, 213).
Aa
White text reads best on this color (5.18:1).
About this color
#3B66D5 is a medium-dark, vivid blue. In OKLCH its lightness is 54%, its chroma 0.178 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.021 away. White text reads best on it, at 5.18:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | vivid (0.178) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.04:1 |
| White text | 5.18:1 |
Values
| HEX | #3B66D5 |
| RGB | rgb(59, 102, 213) |
| HSL | hsl(223, 65%, 53%) |
| OKLCH | oklch(54.2% 0.178 265) |
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 #3B66D5 | 5.18:1 | AA | Lc -80.7 | Fine for body text |
| Black text on #3B66D5 | 4.04:1 | AA large text | Lc 28.8 | Dividers and decoration only |
| #3B66D5 text on white | 5.18:1 | AA | Lc 75.3 | Fine for body text |
| #3B66D5 text on black | 4.04:1 | AA large text | Lc -26.4 | 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
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E2EAFA
oklch(93.6% 0.023 264.5)
-
Step 200
200
#CBD9F7
oklch(88.4% 0.044 265.6)
-
Step 300
300
#A7C0F5
oklch(80.8% 0.08 265)
-
Step 400
400
#799EF0
oklch(70.7% 0.128 264.9)
-
Step 500
500
#5883EB
oklch(63% 0.163 265.1)
-
Step 600
600 (this color)
#3B66D5
oklch(54.2% 0.178 265)
-
Step 700
700
#3158BD
oklch(49.1% 0.165 264.9)
-
Step 800
800
#294899
oklch(42.6% 0.138 265.2)
-
Step 900
900
#253E7A
oklch(37.8% 0.107 264.8)
-
Step 950
950
#162447
oklch(26.9% 0.068 265.6)
#3B66D5 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) | #1A74D9 | 0.037 |
| Deuteranopia (no green cones) | #0066D3 | 0.031 |
| Tritanopia (no blue cones) | #008194 | 0.142 |
| Achromatopsia (no color) | #6D6D6D | 0.178 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B66D5
#3B66D5
oklch(54.2% 0.178 265)
- #8D6900
#8D6900
oklch(54.3% 0.111 84.8)
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 #3B66D5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.021
- Warm Blue #4B57DB ΔE 0.038
- Neon Blue #4361EE ΔE 0.041
- Cerulean Blue #056EEE ΔE 0.046
- Azul #1D5DEC ΔE 0.049
- Dark Periwinkle #665FD1 ΔE 0.053
- Mid Blue #276AB3 ΔE 0.059
- Iris #6258C4 ΔE 0.059
Use #3B66D5 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.