GroupByParam
Syntax
PAGES.GroupByParam PARAM [SORT]
Returns
page.PagesGroup
For the optional sort order, specify either asc for ascending order, or desc for descending order.
{{ range .Pages.GroupByParam "color" }}
  <p>{{ .Key | title }}</p>
  <ul>
    {{ range .Pages }}
      <li><a href="{{ .RelPermalink }}">{{ .LinkTitle }}</a></li>
    {{ end }}
  </ul>
{{ end }}
To sort the groups in descending order:
{{ range .Pages.GroupByParam "color" "desc" }}
  <p>{{ .Key | title }}</p>
  <ul>
    {{ range .Pages }}
      <li><a href="{{ .RelPermalink }}">{{ .LinkTitle }}</a></li>
    {{ end }}
  </ul>
{{ end }}