There are no text color options in New Sites.
If you select emphasis color the text color will change. The colors available vary with different themes.
This text box has an image selected for the background color.
When a lighter image is selected the text color reverts to black.
<h1 style="color:blue;">This is a Blue Heading</h1>
<p style="color:green;">This is done by <b style="color:red;">embedding</b> code in the Embed function.</p>
This in not a very user friendly method, but it is a way of accomplishing it until text color options are added to New Sites.
Inline CSS: https://www.w3schools.com/html/html_css.asp