# Colors

When supplying colors to Chart options, you can use a number of formats. You can specify the color as a string in hexadecimal, RGB, or HSL notations. If a color is needed, but not specified, Chart.js will use the global default color. There are 3 color options, stored at Chart.defaults, to set:

Name Type Default Description
backgroundColor Color rgba(0, 0, 0, 0.1) Background color.
borderColor Color rgba(0, 0, 0, 0.1) Border color.
color Color #666 Font color.

You can also pass a CanvasGradient (opens new window) object. You will need to create this before passing to the chart, but using it you can achieve some interesting effects.

# Patterns and Gradients

An alternative option is to pass a CanvasPattern (opens new window) or CanvasGradient (opens new window) object instead of a string colour.

For example, if you wanted to fill a dataset with a pattern from an image you could do the following.

const img = new Image();
img.src = 'https://example.com/my_image.png';
img.onload = function() {
    const ctx = document.getElementById('canvas').getContext('2d');
    const fillPattern = ctx.createPattern(img, 'repeat');
    const chart = new Chart(ctx, {
        data: {
            labels: ['Item 1', 'Item 2', 'Item 3'],
            datasets: [{
                data: [10, 20, 30],
                backgroundColor: fillPattern
            }]
        }
    });
};

Using pattern fills for data graphics can help viewers with vision deficiencies (e.g. color-blindness or partial sight) to more easily understand your data (opens new window).

Using the Patternomaly (opens new window) library you can generate patterns to fill datasets.

const chartData = {
    datasets: [{
        data: [45, 25, 20, 10],
        backgroundColor: [
            pattern.draw('square', '#ff6384'),
            pattern.draw('circle', '#36a2eb'),
            pattern.draw('diamond', '#cc65fe'),
            pattern.draw('triangle', '#ffce56')
        ]
    }],
    labels: ['Red', 'Blue', 'Purple', 'Yellow']
};
Last Updated: 1/16/2022, 10:06:56 PM