{{ $repoColors := site.Data.repoColors }}
{{ $classNameMap := dict }}
{{ range $language, $unused := $repoColors }}
  {{ $className := printf "background-color-%s" (md5 $language) }}
  {{ $classNameMap = merge $classNameMap (dict $className $language) }}
{{ end }}

{{ $repoLanguages := slice }}
{{ range site.Pages }}
  {{ $matchedClasses := findRE `background-color-[a-f0-9]{32}` .Content }}
  {{ range $matchedClasses }}
    {{ with index $classNameMap . }}
      {{ $repoLanguages = $repoLanguages | append . }}
    {{ else }}
      {{ $repoLanguages = $repoLanguages | append "fallback" }}
    {{ end }}
  {{ end }}
{{ end }}

{{ return (uniq $repoLanguages) }}