#3773DF
Closest named color: Royal Blue (#4169E1). oklch(57.5% 0.177 261), rgb(55, 115, 223).
Aa
Black text reads best on this color (4.68:1).
About this color
#3773DF is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.177 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Royal Blue (#4169E1), ΔE 0.025 away. Black text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.177) |
| Temperature | cool |
| Nearest name | Royal Blue (#4169E1) |
| Black text | 4.68:1 |
| White text | 4.48:1 |
Values
| HEX | #3773DF |
| RGB | rgb(55, 115, 223) |
| HSL | hsl(219, 72%, 55%) |
| OKLCH | oklch(57.5% 0.177 261) |
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 #3773DF | 4.48:1 | AA large text | Lc -76.2 | Fine for body text |
| Black text on #3773DF | 4.68:1 | AA | Lc 33.4 | Non-text elements, placeholder text |
| #3773DF text on white | 4.48:1 | AA large text | Lc 70.7 | Content text, not long reading |
| #3773DF text on black | 4.68:1 | AA | Lc -31.0 | 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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EAFA
oklch(93.5% 0.024 262.1)
-
Step 200
200
#C9DAF7
oklch(88.5% 0.044 261.2)
-
Step 300
300
#A4C2F5
oklch(81% 0.08 260.9)
-
Step 400
400
#73A0F0
oklch(70.7% 0.128 261.3)
-
Step 500
500
#4E86EA
oklch(63.1% 0.162 261)
-
Step 600
600 (this color)
#3773DF
oklch(57.5% 0.177 261)
-
Step 700
700
#245ABC
oklch(49% 0.165 261.1)
-
Step 800
800
#1F4A98
oklch(42.6% 0.137 261.1)
-
Step 900
900
#1F3F79
oklch(37.7% 0.106 261.2)
-
Step 950
950
#132547
oklch(26.9% 0.068 261.9)
#3773DF 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) | #357FE3 | 0.031 |
| Deuteranopia (no green cones) | #0070DD | 0.027 |
| Tritanopia (no blue cones) | #008D9E | 0.139 |
| Achromatopsia (no color) | #777777 | 0.177 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3773DF
#3773DF
oklch(57.5% 0.177 261)
- #9C7000
#9C7000
oklch(57.5% 0.119 81.2)
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 #3773DF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Royal Blue #4169E1 ΔE 0.025
- Cerulean Blue #056EEE ΔE 0.036
- Clear Blue #247AFD ΔE 0.047
- Neon Blue #4361EE ΔE 0.050
- Windows Blue #3778BF ΔE 0.053
- Bright Blue #0165FC ΔE 0.064
- Azul #1D5DEC ΔE 0.064
- Water Blue #0E87CC ΔE 0.066
Use #3773DF 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.