Heat 2 tablespoons olive oil in a large skillet over medium-high heat. Add 1/2 cup diced red onion, 1 cup diced bell peppers (red and yellow) and 1 diced jalapeno; season with salt and pepper. Cook, stirring, until tender, 6 to 8 minutes.
Add 1 cup diced pineapple, 1 tablespoon honey, 1 teaspoon mustard seeds and the zest and juice of 1 lime; cook until thickened, 5 to 8 more minutes. Remove from the heat and add 1/4 cup each chopped cilantro and parsley.
Grill 4 hot dogs over medium-high heat, turning, until marked. Serve on grilled buns with the pineapple relish.