I made a point of collecting only first edition paperbacks as well. But I carried on with the first paperback editions after the hardcovers came out first.
That is correct. The first 13 Travis McGees were originally published in paperback. I just finished collecting First Editions of these. They were published
I didn't have to wait long for the color phrase to show up in The Quick Red Fox. In Chapter 2, page 20, Travis describe the movie star, Lysa Dean as "A vixen.