The CanvasRenderingContext2D.strokeStyle property of the Canvas 2D API specifies the color, gradient, or pattern to use for the strokes (outlines) around shapes. The default is #000 (black).

One of the following:

color

A string parsed as CSS <color> value.

gradient

A CanvasGradient object (a linear or radial gradient).

pattern

A CanvasPattern object (a repeating image).

This example applies a blue stroke color to a rectangle.

HTML

<canvas id="canvas"></canvas>

JavaScript

const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");

ctx.strokeStyle = "blue";
ctx.strokeRect(10, 10, 100, 100);

Result

In this example, we use two for loops and the arc() method to draw a grid of circles, each having a different stroke color. To achieve this, we use the two variables i and j to generate a unique RGB color for each circle, and only modify the green and blue values. (The red channel has a fixed value.)

const ctx = document.getElementById("canvas").getContext("2d");

for (let i = 0; i < 6; i++) {
  for (let j = 0; j < 6; j++) {
    ctx.strokeStyle = `rgb(
        0,
        ${Math.floor(255 - 42.5 * i)},
        ${Math.floor(255 - 42.5 * j)})`;
    ctx.beginPath();
    ctx.arc(12.5 + j * 25, 12.5 + i * 25, 10, 0, Math.PI * 2, true);
    ctx.stroke();
  }
}

The result looks like this:

Screenshot	Live sample

In WebKit- and Blink-based browsers, the non-standard and deprecated method ctx.setStrokeColor() is implemented in addition to this property.

setStrokeColor(color);
setStrokeColor(color, alpha);
setStrokeColor(grayLevel);
setStrokeColor(grayLevel, alpha);
setStrokeColor(r, g, b, a);
setStrokeColor(c, m, y, k, a);

• The interface defining this property: CanvasRenderingContext2D
• CanvasGradient
• CanvasPattern