_Eldar_,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
</head>
<body>
<span id="table1"><table border="">
<caption align="top"><b>Matrix</b></caption>
<tbody><tr align="center">
<th>4x4</th><th>0</th><th>1</th>
</tr>
<tr align="center">
<th>0</th><td bgcolor="#ffffdd">1.5705</td><td bgcolor="#ffffdd">2.0777</td>
</tr> <tr align="center">
<th>1</th><td bgcolor="#ffffdd">5.0777</td><td bgcolor="#ffffdd">6.789</td>
</tr>
</tbody></table>
</span>
<br><a href='javascript:void(0)' onclick='ChangeStyle();return false'> sdfasfd</a>
<script>function ChangeStyle() {
var td = document.querySelectorAll('#table1 td') ;
for (var i=0; i<td.length; i++) {td[i].style.backgroundColor = '#8A2BE2'}
};
</script>
</body>
</html>