Change font size and color inside YAML author

[imladris]

---
title: "Title"
author: |
    | Author One 
    |  Author Two 
    | 
    | Change font size and color
output: 
  bookdown::pdf_document2:
    number_sections: false
---

Above is my YAML.

I want to change the font size to a smaller one and change its color for the last part in author:.

The only relevant suggestion I found is this r - How to change the font color of title, author, date and make it bold in yaml of Rmarkdown? - Stack Overflow

But it doesn't render for me.

[HanOostdijk]

Searching for rmarkdown pdf title size on the internet gives me (you?) some clues.
E.g. this stackoverflow article or the PDF section in the rmarkdown cookbook.
As always: standard reports are easy to make but customized reports can be easy or difficult
(depending on your luck).