The pink walls mean that I need help identifying this sci-fi book

I read this book back in the mid-80’s, but I got the sense that it could well have been written as early as the late 70’s. It may have been one of those Sci-fi Book of the Month Club type books. The plot as I remember it went as follows:

Our protagonist, who I think may have been a journalist from New York (possibly also an ex-military man of some capacity), goes to visit his brother’s (sister’s?) family in an isolated suburban community. He hasn’t visited their home before, and is impressed that the neighborhood is so clean, the people so friendly, etc., etc. Indeed, this little town seems downright perfect. Maybe…too perfect?

You’re damn tooting it is! Turns out the whole town is a secret government experiment in mind control. Citizens are brainwashed and programmed to respond to various cues. One bit that I remember is that the walls of certain rooms in each house are painted a specific color, to elicit a certain emotional response such as anger or passivity. In the end it turns out that the journalist guy is also part of the experiment, programmed to return to the town every so often so that those in charge can gauge how easy it is to discover their secret lab and escape from it. The hero has in fact already been to the town several times before, but his memory was erased each time.

I realize how goofy it is to place a spoiler tag on a book that I don’t even remember the title to, but in case anyone recalls the name of this book someone else may be interested in checking it out. I’d hate to give away the shocking twist ending.

Your description bears a fair resemblance to the tunnel under the world by Frederik Pohl, but unless you are misremembering some of the details, this isn’t the story.

It also has some resemblance to Frank Herbert’s The Santaroga Barrier … but I don’t think it’s that either …