The production team has said that the characters wear colors that either complement or contrast with Brenda's outfit in each scene. Those that complement her colors are on her side or will be helpful to the investigation. Those that contrast are her opposition and/or the guilty party.
The cat that played 'Kitty' was diagnosed with a serious kidney condition. Rather than replace the cat, it was decided to write the illness into the story." The real cat died shortly after his final episode was filmed.
Kyra Sedgwick had doubts about taking the role because it meant being away from her family for a few months. Knowing it was a great opportunity, her husband Kevin Bacon agreed not to work much and stay home with their children (as Sedgwick had done many times)
Each series of "The Closer" has a theme on which its episodes are based. For Season 1, the theme is a woman in a man's world. Season 2 is about partnerships. Season 3 is family. Season 4 is described by James Duff as a meditation on power in its many forms - natural and human. The theme for Season 5 is change, while season six seems to deal with adjustment.
It appears that among Lt. Provenza's 4 or more ex-wives there was a Heather, a Liz (who corrected his grammar), and a Sharon (who always had to be right). His 2nd wife and 4th wife are actually the same woman.
In December 2010, Kyra Sedgwick announced that the show would end after season 7. TNT made a statement confirming it, implying that it was mostly Sedgwick's decision with her power as a producer. A few weeks later, it was announced that the show would have a spin-off once season 7 was over, revealing the idea that most of the cast and crew were willing to produce more stories for the characters.