highcharts custombutton hover and press changing colors by default
<p>I am trying to create custom buttons in highcharts using 
"chart.renderer.button" with a default color. however on hover or press the color seems to change by default... i donot want the color to change on hover and button press. Please let me know if there is a simple fix which can be done</p>

<p>here is the fiddle: 
<a href="http://jsfiddle.net/NxK39/81/" rel="nofollow">http://jsfiddle.net/NxK39/81/</a></p>

<pre><code>    *var testbutton = chart.renderer.button('button1',0, 10)
        .attr({
            id: 'button1',
            fill:'#000000',
            height:20,
            width:40
        })
        .on('click', function () {
        alert("test1");

        })
        .css({
            color: '#FFFFFF',
            fontSize: '12px',
            fontWeight: 'bold'
        })
        .add();*
</code></pre>