Try adding colspan, followed by style, like this:
<th colspan="5" style="color:black">test</th>
I agree with batraaf, but it doesn't explain why. You can add many attributes to a html element, you just need to seperate them with a space, here is other example:
<img src="#" alt="my image">
Thank you batraaf and stemim94! forgot to write color after style, ha ha. Thanks for the help!