[Chartjs]-Applying background-color in bar chart using chart.js

Using Chart.js plugins, you can create your own backgroundColor & borderColor properties and then assign them to the chart :

var randomColorPlugin = {

    // We affect the `beforeUpdate` event
    beforeUpdate: function(chart) {
        var backgroundColor = [];
        var borderColor = [];

        // For every data we have ...
        for (var i = 0; i < chart.config.data.datasets[0].data.length; i++) {

            // We generate a random color
            var color = "rgba(" + Math.floor(Math.random() * 255) + "," + Math.floor(Math.random() * 255) + "," + Math.floor(Math.random() * 255) + ",";

            // We push this new color to both background and border color arrays
            // .. a lighter color is used for the background
            backgroundColor.push(color + "0.2)");
            borderColor.push(color + "1)");
        }

        // We update the chart bars color properties
        chart.config.data.datasets[0].backgroundColor = backgroundColor;
        chart.config.data.datasets[0].borderColor = borderColor;
    }
};

You can see a working example on this jsFiddle. Every time you run the code, you’ll get different colors.
Here is one of the result :