Chris Brown -- Repping Bloods Gang in Hawaii

Another brilliant move by Chris Brown -- the singer has affiliated himself with a dangerous street gang in L.A. called the Pirus (a subset of the Bloods) ... and he's bragging about it all the way to Hawaii.

Sources tell TMZ, Brown was in Honolulu Thursday, where he hired a guide to take him and his entourage around to places where they could legally spray paint.

Keeping it "legal" was responsible, but then Brown tagged up his signature monster artwork with the phrase "Fruits Piru," an apparent reference to the Fruit Town Piru gang ... next to the phrase, "F*** police."

Brown's even been claiming Piru on Twitter. He's gotten so cocky, he called out Jay Z for not letting Beyonce collaborate with him, and bragging he's not worried about Mr. Z because he's got Blood ties.

Strange ... just last year Chris tweeted, "I'm no gangbanger! where im from we say cuz,blood, folk, woadie, homie, patna, its slang and ebonics! US KIDS USE THESE TERMS."

For the record, Brown's not doing anything illegal by giving a shoutout to a violent gang -- it doesn't even violate his probation. It's just not smart for someone with his record. Really not smart.

But at least it helps explain Chris' red outfits and cars ...