RCsocial.net now supports full-text search!
It will now return results for any text contained in past toots you touched (posted, received, favourited or boosted -- e.g. "liturgical color").
Techies: this optional feature of Mastodon is provided via integration with elasticsearch.
Mastodon's primary developer is Eugen Rochko. He wrote about the privacy design decisions here:
RCsocial.net — a friendly social networking space for those with an interest in Catholicism.