Prepare grill to medium-high heat.
Place bell peppers on grill rack. Grill, without lid, over medium-high heat 5 to 7 minutes, turning frequently, until peppers blister. Place peppers in a zip-top plastic bag; seal. Let stand 15 minutes. Peel peppers; remove and discard seeds. Cut peppers into 1/2-inch pieces.
Combine bell peppers and remaining ingredients in a medium bowl; toss well.