[Solved]-Changing bar colors on data that is within the same series data-Highcharts

the details for how to do this are clear in the api documentation: http://api.highcharts.com/highcharts#series.data.color, you can set the color on an individual data point, see here:

so, from your example this does what you want:

var chart = new highcharts.chart({
    chart: {
        renderto: 'container',
        type: "bar"
    },
    xaxis: {
        categories: [ "july", "august", "september", "october"]
    },
    series: [{
        data: [2341, 1245, 989, { color: 'red', y: 1829 } ],
    }]
});

fiddle

if you want to change the colour later then the linked answer in the comments shows how -- there is a loop there changing all the points, you can use it to change just one.