Answers for "bootstrap class name for red text"

change bootstrap background color

<style type="text/css">
   body { background: navy !important; } /* Adding !important forces the browser to overwrite the default style applied by Bootstrap */
</style>

bootstrap color a div

use something like :
<div class="container alert alert-success">
   <div class="row">
      <div class="col">I'm your content inside the grid!</div>
   </div>
</div>