Angular Google Charts: how to set different colors to columns in column chart

Question

I am using Angular 9 + Google Charts via npm: npm install angular-google-charts

I want to set different colors to all columns in column charts but it's setting first color to all columns.

Did anybody encounter such problem or have any solution for setting different colors to columns in google column chart?

HTML:

<google-chart #chart
   [title]="title"
   [type]="type"
   [data]="data"
   [columns]="columnNames"
   [options]="options"
   [width]="width"
   [height]="height">
</google-chart>

TypeScript:

export class ColumnChartComponent[![enter image description here][1]][1] {
  title = 'Population (in millions)';
  type = 'ColumnChart';
  data = [
     ["2012", 900],
     ["2013", 1000],
     ["2014", 1170],
     ["2015", 1250],
     ["2016", 1530]
  ];
  columnNames = ['Year', 'Asia'];

  // chart options in which I am setting colors
  options = {
    colors: ['#5cb85c', '#f0ad4e', '#d9534f', '#5bc0de', '#f6c7b6'],
  };

  width = 550;
  height = 400;
}

Answer 1

each entry in the colors array, applies to each series in the data table.
the data table in the example only has one series, or y-axis column.

data = [
   ["2012", 900],
   ["2013", 1000],
   ["2014", 1170],
   ["2015", 1250],
   ["2016", 1530]
];
columnNames = ['Year', 'Asia'];

in order to have a different color for each bar using the colors option,
each value needs to be in a different data table column.

eg

data = [
   ['Asia', 900, 1000, 1170, 1250, 1530]
];
columnNames = ['Country', '2012', '2013', '2014', '2015', '2016'];

---

another option is to use a style column role.
this option allows you to add the color to the data table,
and color each bar individually, without having multiple series.

data = [
   ["2012", 900, '#5cb85c'],
   ["2013", 1000, '#f0ad4e'],
   ["2014", 1170, '#d9534f'],
   ["2015", 1250, '#5bc0de'],
   ["2016", 1530, '#f6c7b6']
];
columnNames = ['Year', 'Asia', {role: 'style', type: 'string'}];

the only drawback to using the style role,
the legend will not match the colors.
it uses the same approach as the colors option,
and will only display the one series,
using the first color in the colors option.

Answer 2

Well, As there isn't a straight forward solution available get the different colors for all columns in angular-google-column-chart with nice colored legends. I came up with a trick cum workaround to get the desired result using stacked column chart to achive this.

TypeScript:

title = 'Resources Status Overview';
  type = 'ColumnChart';

// => here is the trick. set single colored value for the column and rest to 0.
  data = [
    ["Ready", 500, 0, 0, 0],
    ["Pending", 0, 360, 0, 0],
    ["Deployed", 0, 0, 410, 0],
    ["Other", 0, 0, 0, 200],
  ];

  columnNames = ['Status', 'Ready', 'Pending', 'Deployed', 'Other'];

  options = {
    hAxis: {
      title: 'Status'
    },
    vAxis: {
      minValue: 0
    },
    isStacked: true,
    colors: ['#5cb85c', '#f0ad4e', '#d9534f', '#5bc0de']
  };

  width = 600;
  height = 400;

It's a trick with the data set. In the stacked columns, set rest of the colors to 0 and keep the value in only for the matching color and you will get the nice column chart with legends. If you have limited data then this would be a nice solution for you.