Download the latest **[release](https://git.la10cy.net/DeltaLima/flatpress-theme-rainbow/releases)** and extract rainbow_vX.Y.Z.zip to your `fp-interface/themes/` folder.
Actually (26.06.2023) I dont know why, I havent looked for it, but when have comments on a blog post, the footer is also a Link pointing to the comments section.