chart.js set one bar as different colour?

Question

So I have this code which is happily displaying a graph in the format I require:

<script>var ChartTitleOps = {

showTooltips: true,
tooltipFillColor: "#e64c65",
tooltipFontFamily: "'Bree Serif', sans-serif",
tooltipFontColor: "#fff",
tooltipTemplate: "<%if (label){%><%=label%> <%}%>(<%= value %> votes)",
barValueSpacing : 2,
scaleLineWidth: 10,

    scaleFontFamily: "'Bree Serif', sans-serif",responsive: false,animation: false,maintainAspectRatio: false,scaleIntegersOnly: true,scaleShowGridLines : false,scaleBeginAtZero : true,scaleFontSize: 17,scaleFontColor: "#FFFFFF",scaleOverride:true,scaleSteps:<?php echo $highestVoteCount ?>,scaleStepWidth:1,scaleStartValue:0,scaleGridLineColor : "#1f253d"}; var ChartTitleData = {labels : [<?php styleFinishedVoteAmounts($votesPlaced); ?>],datasets : [{
                fillColor   : "rgba(52,104,175,0.7)",
                strokeColor : "rgba(52,104,175,1)",
                data        : [<?php styleFinishedVoteCount($VoteCounts); ?>]
            }]};var wpChartChartTitleBar = new Chart(document.getElementById("ChartTitle").getContext("2d")).Bar(ChartTitleData,ChartTitleOps);
</script>

I would like to have one of the bars within that graph shows as a different colour from those that are set in the code above.

Possible duplicate of [Different color for each bar in a bar chart; ChartJS](https://stackoverflow.com/questions/25594478/different-color-for-each-bar-in-a-bar-chart-chartjs) — thanksd, Jun 14 '17 at 19:14

score 5 · Accepted Answer · answered Feb 10 '15 at 12:01

You can change the color of a bar element after you have created your chart.

After new Chart() statement you can access and modify the chart element properties and update the chart like this :

var wpChartChartTitleBar = new Chart(document.getElementById("myChart").getContext("2d")).Bar(ChartTitleData, ChartTitleOps);

// Change 2nd bar to red (display).
wpChartChartTitleBar.datasets[0].bars[1].fillColor = "rgba(229,12,12,0.7)";
wpChartChartTitleBar.datasets[0].bars[1].strokeColor = "rgba(229,12,12,1)";

// Change 2nd bar to red (highlight setting on mouse over)
wpChartChartTitleBar.datasets[0].bars[1].highlightFill = "rgba(0,229,0,0.7)";
wpChartChartTitleBar.datasets[0].bars[1].highlightStroke = "rgba(0,229,0,1)";

wpChartChartTitleBar.update();

See a fiddle of it here.

Worked perfectly! thanks so much for taking the time to help me! :) — Gary Stewart, Feb 12 '15 at 11:56

David Metcalfe · Answer 2 · 2020-04-03T09:34:14.590

Since rtome's method doesn't seem to work in newer versions of Chart.js, here's a working example of differing bar colours for the current version (2.9.3 as of this post).

var ctx = document.getElementById("myChart").getContext("2d");
var chart = new Chart(ctx, {
  // The type of chart we want to create
  type: "horizontalBar",

  // The data for our dataset
  data: {
    labels: ["January", "February", "March", "April", "May", "June", "July"],
    datasets: [{
      label: "My First dataset",
      backgroundColor: [
        "rgb(255, 99, 132)",
        "rgb(255, 159, 64)",
        "rgb(255, 205, 86)",
        "rgb(75, 192, 192)",
        "rgb(54, 162, 235)",
        "rgb(153, 102, 255)",
        "rgb(201, 203, 207)"
      ],
      borderColor: "rgb(255, 99, 132)",
      data: [3, 10, 5, 2, 20, 30, 45]
    }]
  },

  // Configuration options go here
  options: {}
});

canvas {
  -moz-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
}

body {
  margin-top: 35px;
}

#container {
  width: 95%;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: auto;
}

<html>

<head>
  <title>Bar colour example</title>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
</head>

<body>
  <div id="container">
    <canvas id="myChart"></canvas>
  </div>
</body>

</html>

Thank you! I was looking at a way to give the label a different color when it met a certain criteria. but when I saw this snippet and realized "backgroundColor" could be an array. I knew this solution would work as well! — Cees, Oct 05 '20 at 04:02

chart.js set one bar as different colour?

2 Answers2