When one late-night door closes, another opens.

"The Late Show with Stephen Colbert" announced that George Clooney and Kendrick Lamar will be his first guests -- while the Ed Sullivan Theater got a new facade on Friday.

Colbert tweeted on Friday that "George Clooney will be my first-ever #LSSC guest on September 8th! Could one of you let him know?"

Colbert announced on Monday that his first musical guest will be Kendrick Lamar, who was the last musical guest on "The Colbert Report."

Meanwhile, changes were afoot outside the Ed Sullivan Theater where Colbert will be taking over from David Letterman. A new marquee that read "The Late Show with Stephen Colbert" could be seen outside the Manhattan theater on Friday.

In the hiatus between shows, Colbert has been busy making viral videos -- and visiting his old friend Jon Stewart for Stewart's final episode of "The Daily Show" on Thursday night.