How to set tooltip border color from series in Highcharts
<p>By default, the border takes the color of the corresponding series or point. But I'd like to set a different color to the tooltip of a certain data point, without changing the color of the data point itself.</p>

<p>I needed something like this:</p>

<pre><code>series: [ { x:1, value: 2.34, tooltip:{borderColor: '#112233'}  }, ... ];
</code></pre>

<p>Sadly this property can not be set from a series.</p>

<p>By setting a formatter callback function in the tooltip configuration one can only define the inner HTML of the tooltip, i.e. the border color can not be changed from within this function.</p>

<p>Can this only be achieved by some CSS trickery? </p>