There are so many changes in the Netflix series, they no longer resemble the books.
Season 3 about Penelope and Colin is totally different. The angst in the book is discovering the identity of Mrs.Whistledown. When Colin discovers it’s Penelope his is angry and concerned for her safety but realizes he is also jealous because she achieved something, her life’s work, which is what Colin has been searching for. Colin is later convinced by Penelope to publish his travel journals.
In book 4 of the series, there are no rival suitors for Penelope as she has been in love with Colin for years.
Disappointed in the TV series and surprised Julia Quinn allowed her books to be so distorted.
READ the books.