The text would be barely visible if you color it white and place it on a background image that is predominantly white in color. You can however use CSS to add a transparent light-dark background between the text and the image and it would be perfectly visible.

Also see: Font Colors for Video Captions

<h1><span>The quick brown fox jumped over the lazy dog</span></h1>

<style>
  h1 {
    width: 70%;
    margin: auto;
    color: #fff;
    font-family: "Lato", sans-serif;
    font-size: 48px;
    font-weight: 400;
    text-align: center;
    line-height: 80px;
  }

  h1 span {
    background: rgba(0, 0, 0, 0.5);
    -moz-box-shadow: 0 0 0 10px rgba(0, 0, 0, 0.5);
    -webkit-box-shadow: 0 0 0 10px rgba(0, 0, 0, 0.5);
    box-shadow: 0 0 0 10px rgba(0, 0, 0, 0.5);
  }
</style>