8.2 Appearance and style

There are several options that control the appearance of reveal.js presentations:

theme specifies the theme to use for the presentation (available themes are "default", "simple", "sky", "beige", "serif", "solarized", "blood", "moon", "night", "black", "league", and "white").
highlight specifies the syntax highlighting style. Supported styles include "default", "tango", "pygments", "kate", "monochrome", "espresso", "zenburn", and "haddock". Pass null to prevent syntax highlighting.
center specifies whether you want to vertically center content on slides (this defaults to false).
smart indicates whether to produce typographically correct output, converting straight quotes to curly quotes, --- to em-dashes, -- to en-dashes, and ... to ellipses. Note that smart is enabled by default.

For example:

---
output:
  revealjs::revealjs_presentation:
    theme: sky
    highlight: pygments
    center: true
---

If you need smaller text for certain paragraphs, you can enclose text in the <small> tag. For example:

<small>This sentence will appear smaller.</small>