HTML for a table with cells that have red backgrounds

[rc]

Currently I'm sending an HTTP request with the following:

{"type":"page","title": "Comparison","ancestors":[{"id":111111111}], "space":{"key":"aaaa"},"body":{"storage":{"value": "<table><tr><td><strong>Category</strong></td><td><strong> Duration </strong></td><td><strong>Duration</strong></td></tr><tr><td>File System Creation</td><td class="highlight-red" data-highlight-colour="red" title="Background colour : Red">0:52 </td><td class="highlight-red" data-highlight-colour="red" title="Background colour : Red">0:26</td></tr></table>", "representation":"storage"}}}

This doesn't work and provides the error:
{
"message": "",
"reason": "Internal Server Error",
"statusCode": 500
}

It works without the "class="highlight-red" data-highlight-colour="red" title="Background colour : Red"". 

How could I fix this?