Editing Template:StyledTable/styles.css

@media screen {
  table.styled-table {
    background-color: #f8f8f8;
    color: #202122;
  }

  html.skin-theme-clientpref-night table.styled-table,
  html.skin-theme-clientpref-os table.styled-table {
    background-color: #1e1f21;
    color: #eaecf0;
  }

  table.styled-table th {
    background-color: #4B9CD3;
    color: white;
  }

  html.skin-theme-clientpref-night table.styled-table th,
  html.skin-theme-clientpref-os table.styled-table th {
    background-color: #335577;
    color: #ffffff;
  }

  table.styled-table {
    border-radius: 8px;
    border: 1px solid #a2a9b1;
  }
}