Where does “rubedo” come from?

rubedo (Latin) comes from Latin rubeō, from Proto-Italic ruðēō, from Proto-Indo-European h₁rudʰéh₁ti, from Proto-Indo-European h₁rewdʰ- — red.

Ancestry of “rubedo”, step by step

Step	Language	Word	Meaning
1	Latin	rubeō	—
2	Proto-Italic	ruðēō	—
3	Proto-Indo-European	h₁rudʰéh₁ti	to be red
4	Proto-Indo-European	h₁rewdʰ-	red

rubedo — Etymology, Origin & Word History | Etymology Explorer