The singer, who along with Erasure partner Vince Clarke co-headlined the tour last year, will take some time off from recording his sophomore solo album in London for the shows.
Bell will join Lauper and friends beginning June 21 at Cynthia Woods Mitchell Pavilion in Houston.
Shows featuring Bell include Superpages.com Center in Dallas (June 22), Dodge Theater in Phoenix (June 25), Viejas Concerts in the Park in Alpine, Calif. (June 27), the Greek Theatre in Los Angeles (June 28) and the Greek Theatre in Berkeley, Calif. (June 29).
Other acts on the rotating lineup for the tour, which kicks off Gay & Lesbian Pride Month on May 31 at Boston's Bank of America Pavilion, include The B-52's, Rosie O'Donnell, Tegan and Sara, The Cliks, Indigo Girls, Joan Armatrading, Joan Jett & The Blackhearts, Regina Spektor, Wanda Sykes, Nona Hendryx, Deborah Cox and host Carson Kressley.
Complete info on the roster for each city, along with ticket info, is available at TrueColorsTour.com.
Pollstar spoke with Bell last year about Erasure's involvement with the tour.
It seems Lauper is a big fan of the band, and they share an agent in the States, Jonny Podell.
The singer said the admiration is mutual, and he thinks doing a tour that supports the HRC is vital.
"I think it's quite important, because of things like Guantanamo Bay in the U.S.," Bell said. "I think human rights have kind of been put onto the back burner.
"Because people look up to America, and they're kind of giving the example that you can just pop people in prison and keep them there forever and ever without question, torture just seems to be more and more widespread around the world.
"I just think it's really important to reiterate that human beings have rights and I think the Gay and Lesbian movement is kind of at the forefront of that."
Although Bell said he thinks most people in the country don't support the kind of things that have been going on over the past seven years, he recounted a story about a concert in the States where the reaction from the crowd surprised him.
"One time we played San Francisco, just when the first Gulf War started. It was at the Civic Auditorium and there were all of these protests going on and they were arresting people left and right.
"I said, 'Three cheers for the peace protestors!' and half of the audience booed. I was quite shocked, but then I thought, 'Well, we've got Republican fans too.'"
Bell said he learned after his solo debut was released in 2005 that doing solo gigs is very different from doing Erasure shows.
"When Electric Blue came out, the best way we could work it was by me going and doing DJ sets and then doing a PA afterwards. It was quite heavy work. It really made me appreciate those disco divas that are on the circuit all the time. It's really, really hard work.
"It's much nicer, I think, to have a group of people around you, like a support system, rather than being on your own."