Heat oven to 400ºF. Arrange salmon fillets on a baking sheet, drizzle with the olive oil and season with salt and pepper. Roast until the salmon is tender and flakey, about 10 minutes.
Heat a medium sauté pan over medium heat, add the butter and allow to melt. Cook the butter, swirling it around the pan occasionally, until the butter is toasty-brown color and has a nutty aroma, about 5 minutes. Once this happens immediately remove the brown butter to a small bowl.
Wipe out the sauté pan and return it to medium heat. Add 2 tablespoons of the brown butter to the pan and heat through. Add the rice into the pan in an even layer and cook, untouched, until the bottom is crispy and golden brown, about 3 minutes. Stir and cook for an additional 3 minutes. Divide the crispy rice among serving bowls.
In another medium mixing bowl toss the blood orange, orange and grapefruit segments with the fennel and divide among the serving bowls and top each with a piece of the cooked salmon.
Drizzle each bowl with the remaining brown butter and serve immediately.