#3B78DD
Closest named color: Royal Blue (#4169E1). oklch(58.5% 0.167 259.9), rgb(59, 120, 221).
Aa
Black text reads best on this color (4.91:1).
About this color
#3B78DD is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.167 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.039 away. Black text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.167) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.91:1 |
| White text | 4.27:1 |
Values
| HEX | #3B78DD |
| RGB | rgb(59, 120, 221) |
| HSL | hsl(217, 70%, 55%) |
| OKLCH | oklch(58.5% 0.167 259.9) |
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 #3B78DD | 4.27:1 | AA large text | Lc -74.6 | Content text, not long reading |
| Black text on #3B78DD | 4.91:1 | AA | Lc 35.0 | Non-text elements, placeholder text |
| #3B78DD text on white | 4.27:1 | AA large text | Lc 69.1 | Content text, not long reading |
| #3B78DD text on black | 4.91:1 | AA | Lc -32.5 | Non-text elements, placeholder text |
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
#E2EAF9
oklch(93.5% 0.022 263.2)
-
Step 200
200
#C9DAF5
oklch(88.4% 0.042 259.6)
-
Step 300
300
#A5C2F2
oklch(80.9% 0.075 260.4)
-
Step 400
400
#74A1EB
oklch(70.7% 0.12 260)
-
Step 500
500
#4F87E5
oklch(63% 0.154 260.1)
-
Step 600
600 (this color)
#3B78DD
oklch(58.5% 0.167 259.9)
-
Step 700
700
#255CB7
oklch(49.1% 0.156 260)
-
Step 800
800
#204C94
oklch(42.8% 0.128 259.8)
-
Step 900
900
#1F4076
oklch(37.7% 0.1 259.8)
-
Step 950
950
#132645
oklch(27.1% 0.063 259.7)
#3B78DD 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) | #4382E1 | 0.029 |
| Deuteranopia (no green cones) | #1E73DB | 0.025 |
| Tritanopia (no blue cones) | #0090A0 | 0.131 |
| Achromatopsia (no color) | #7A7A7A | 0.167 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B78DD
#3B78DD
oklch(58.5% 0.167 259.9)
- #A17200
#A17200
oklch(58.5% 0.121 79.9)
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 #3B78DD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.039
- Windows Blue #3778BF ΔE 0.047
- Cerulean Blue #056EEE ΔE 0.048
- Clear Blue #247AFD ΔE 0.049
- Water Blue #0E87CC ΔE 0.054
- Dark Sky Blue #448EE4 ΔE 0.060
- Neon Blue #4361EE ΔE 0.063
- Soft Blue #6488EA ΔE 0.065
Use #3B78DD 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.