The 49-year-old actress and television personality discussed her friendship with Rinna, 56, during Wednesday's at-home episode of Watch What Happens Live.
Richards and Rinna clash in Real Housewives of Beverly Hills Season 10, which premiered on Bravo in April. During a previous appearance on WWHL, Rinna said Richards' anger with her was at a "10" out of 10 during the season.
Richards weighed in on Rinna Wednesday.
"There's definitely been a change in our friendship. You know, people will see that as the show plays out," she said. "We've been friends, though, for over 20 years and we never know what's going to happen in life. So, we'll see."
Richards also responded to her Real Housewives of Beverly Hills co-star Kyle Richards calling her a "ragamuffin" on the show.
"I didn't know she had called me a ragamuffin until I saw the episode," Richards said with a laugh. "I actually thought it was funny."
"I think it's good to not be so judgmental with all of us and just have fun with it," she added. "Yes, I do like to be casual, but I also do like glam as well."
Richards poked fun at Kyle Richards' comment on Instagram last week by sharing photos of herself on magazine covers throughout the years. She captioned the post, "Going down memory lane with this #ragamuffin."
Kyle Richards responded in the comments.
"Denise, you are absolutely beautiful. There is no doubt about that. I was exhausted, emotional & felt everyone was coming at me. I got upset because I thought you of all people would get what I was saying because you yourself say you don't get the glam thing and just wear a messy top knot. So I didn't get the sudden change," the star said.
"With that said, I still regret that comment and was not the best version of myself that night. My apologies," she added.
Richards stopped filming Real Housewives of Beverly Hills in December. Her co-star Garcelle Beauvais said on WWHL in April that Richards is "doing great" following drama with the cast.