set different colors for each column in highcharts

Here is another solution with the latest version of Highcharts (currently 3.0).

Set the colorByPoint option to true and define the color sequence that you want.

options = {
    chart: {...},
    plotOptions: {
        column: {
            colorByPoint: true
        }
    },
    colors: [
        '#ff0000',
        '#00ff00',
        '#0000ff'
    ]
}

Here is an example based upon Highcharts Column with rotated labels demo