Update: I'm leaving the answer below this line intact in case there are those out there who are using an older version, but per a later comment, KendoUI now allows you to override styles for individual points in a series.

I don't believe you can, in the current version. That said, you can hack your way around the limitation.

You'll need to create two data series - one for your highlighted data, and one for everything else. Add both to you chart, and set them to stacked.

Here's a jsFiddle I put together to illustrate: http://jsfiddle.net/LyndsySimon/9VZdS/. It depends on KendoUI's CDN, so if it breaks in the future I apologize.

Here is the Javascript for reference:

$(function() {

    var dataset = new Array(1,2,3,null,5,6);

    var highlighted = new Array(null,null,null,4,null,null);



    $('#chart').kendoChart({

        theme: 'metro',

        seriesDefaults: {

            type: 'column',

            stack: true

        },

        series: [

            {

                name: 'Not Highlighted',

                data: dataset,

                color: '#609'

            },

            {

                name: 'Highlighted',

                data: highlighted,

                color: '#f03'

            }

        ]

    })

});​