TCM uses the DVD transfer for its airing and it looks good...
But it's probably from separations and is a little soft. The color is wonderful, though.
The '56 version was digitally restored completely by Cinesite (along with To Kill a Mockingbird and To Hell and Back), finishing in 2001. The DVD was released in 2001, but likely before the digital restoration was completed. After all, the DVD uses the version of the film with the Universal logo replacing the Paramount one.