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This should be simple. How can I assign my own colors to the bars in Google Gantt Charts? The gantt is ignoring my colors and automatically assigning blue, red and yellow colors (in that order) to the bars and I can't seem to figure out the problem. Can someone please point out if I am missing something here or is it not supported at all at this time?

Here is what I have: 

function drawChart() {

      var data = new google.visualization.DataTable();
      data.addColumn({ type: 'string', id: 'task_id' }, 'Task ID');
      data.addColumn({ type: 'string', id: 'task_name' }, 'Task Name');
      data.addColumn({ type: 'string', id: 'resource' }, 'Resource');
      data.addColumn({ type: 'date', id: 'start_date' }, 'Start Date');
      data.addColumn({ type: 'date', id: 'end_date' }, 'End Date');
      data.addColumn({ type: 'number', id: 'duration' }, 'Duration');
      data.addColumn({ type: 'number', id: 'percent_complete' }, 'Percent Complete');
      data.addColumn({ type: 'string', id: 'dependencies' }, 'Dependencies');

      data.addRows([
        ['Research', 'Find sources', null,
         new Date(2015, 0, 1), new Date(2015, 0, 5), null,  100,  null],
        ['Write', 'Write paper', 'write',
         null, new Date(2015, 0, 9), daysToMilliseconds(3), 25, 'Research,Outline'],
        ['Cite', 'Create bibliography', 'write',
         null, new Date(2015, 0, 7), daysToMilliseconds(1), 20, 'Research'],
        ['Complete', 'Hand in paper', 'complete',
         null, new Date(2015, 0, 10), daysToMilliseconds(1), 0, 'Cite,Write'],
        ['Outline', 'Outline paper', 'write',
         null, new Date(2015, 0, 6), daysToMilliseconds(1), 100, 'Research']
      ]);


      var colors = [];
      var colorMap = {
          write: '#e63b6f',
          complete: '#19c362'
      }
      for (var i = 0; i < data.getNumberOfRows(); i++) {
          colors.push(colorMap[data.getValue(i, 2)]);
      }

        var options = {
          height: 275,
          gantt: {
            criticalPathEnabled: true,
            criticalPathStyle: {
              stroke: '#e64a19',
              strokeWidth: 5
            }
          },
          colors: colors
        };

        var chart = new google.visualization.Gantt(document.getElementById('chart_div'));
        chart.draw(data, options);
      }
Lightning Evangelist
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3 Answers3

13

There is an optiongantt.palette which takes an array of objects.

var options = {
  gantt: {
    palette: [
      {
        "color": "#cccccc",
        "dark": "#333333",
        "light": "#eeeeee"
      }
    ]
  }
}

By providing your own array of objects, you can override the default palette.

This is the default palette that the chart uses:

[
  {
    "color": "#5e97f6",
    "dark": "#2a56c6",
    "light": "#c6dafc"
  },
  {
    "color": "#db4437",
    "dark": "#a52714",
    "light": "#f4c7c3"
  },
  {
    "color": "#f2a600",
    "dark": "#ee8100",
    "light": "#fce8b2"
  },
  {
    "color": "#0f9d58",
    "dark": "#0b8043",
    "light": "#b7e1cd"
  },
  {
    "color": "#ab47bc",
    "dark": "#6a1b9a",
    "light": "#e1bee7"
  },
  {
    "color": "#00acc1",
    "dark": "#00838f",
    "light": "#b2ebf2"
  },
  {
    "color": "#ff7043",
    "dark": "#e64a19",
    "light": "#ffccbc"
  },
  {
    "color": "#9e9d24",
    "dark": "#827717",
    "light": "#f0f4c3"
  },
  {
    "color": "#5c6bc0",
    "dark": "#3949ab",
    "light": "#c5cae9"
  },
  {
    "color": "#f06292",
    "dark": "#e91e63",
    "light": "#f8bbd0"
  },
  {
    "color": "#00796b",
    "dark": "#004d40",
    "light": "#b2dfdb"
  },
  {
    "color": "#c2185b",
    "dark": "#880e4f",
    "light": "#f48fb1"
  }
]
V Soren
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    Thank you for this - works great and I couldn't find it in the Google documentation! – Robert D May 19 '18 at 17:27
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    Do you know what each of the parameters mean? From playing around with it, "color" seems to be the color of the unfilled bar. "dark" is the color used to fill it up, but I can't seem to figure out what "light" is – user366818 Apr 20 '20 at 15:12
  • This still isn't in the Google documentation. – alstr May 03 '22 at 13:47
  • Great! You saved me :) I really wonder why this is not in the documentation – peace_love Mar 07 '23 at 07:36
  • Are the objects in the palette array ordered? I group my task bars by Resource and want Resources specific colors. – Tom Jul 08 '23 at 00:51
1

I figured out a hacky way of doing it. You basically have to listen to every single event fired by the chart and override them with a function that colors the chart.

Clay Risser
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0

This is pretty old, but just in case anyone needs to do this... Not a super elegant solution, but it works.

function changeColors() {
$("text[fill='#5e97f6']").attr('fill',"#0099D8"); // Left Text
$("rect[fill='#5e97f6']").attr('fill',"#0099D8"); // Full bar
$("path[fill='#2a56c6']").attr('fill', '#006B99'); // Percentage completed
$("rect[fill='#2a56c6']").attr('fill', '#0099D8'); // Hover Full Bar
$("path[fill='#204195']").attr('fill', '#006B99'); // Hover Percentage

// Change Old red to new Red
$("text[fill='#db4437']").attr('fill',"#D41647");
$("rect[fill='#db4437']").attr('fill',"#D41647");
$("path[fill='#a52714']").attr('fill', '#A21135');
$("rect[fill='#a52714']").attr('fill', '#D41647');
$("path[fill='#7c1d0f']").attr('fill', '#A21135');

// Change Old Yellow to new Yellow
$("text[fill='#f2a600']").attr('fill',"#FCB813");
$("rect[fill='#f2a600']").attr('fill',"#FCB813");
$("path[fill='#ee8100']").attr('fill', '#C98e03');
$("rect[fill='#ee8100']").attr('fill', '#FCB813');
$("path[fill='#b36100']").attr('fill', '#C98e03');

}

...and then after you draw the chart, add a "ready" and these other event listeners to run changeColors any time anything happens.

chart.draw(data, options);
google.visualization.events.addListener(chart, 'ready', changeColors);
google.visualization.events.addListener(chart, 'onmouseover', changeColors);
google.visualization.events.addListener(chart, 'onmouseout', changeColors);
google.visualization.events.addListener(chart, 'select', changeColors);
google.visualization.events.addListener(chart, 'error', changeColors);
google.visualization.events.addListener(chart, 'click', changeColors);
google.visualization.events.addListener(chart, 'animationfinish', changeColors);

Issues:

There seems to be some switching of the colors in certain situations, as you mouse around on it.

jeffsdata
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