Thanks to all who provided input on the proposed cover design I posted.
Everyone who responded seemed to feel strongly about it, some favorably and some not-so-favorably. The colors, style and illustration gave a few people the idea the story was a romance set in an earlier era. As the book is a contemporary mystery/thriller, it was not the impression I was going for.
This was really helpful information.
It is good for a cover to provoke strong feelings, but it is not good to confuse the readers or set them up for disappointment when the cover is a mismatch for the style or genre of the book inside.
While we may not be able to accurately judge a book by its cover, most potential readers use a book cover to assess whether the book will be to their tastes. A cover can make or break a book, and can be as important as the story inside.
So, out with that cover design and back to the drawing board.