How to Make It
Preheat oven to 350°F. Scrub beets, and trim greens to 1 inch. Wrap red beets in a single layer in an aluminum foil pouch, closing it tightly. Wrap yellow beets in a second foil pouch. Bake in preheated oven until tender, about 1 hour and 15 minutes. Uncover and cool completely, about 30 minutes.
Rub beets to remove skins; slice into 1/4-inch-thick rounds. Arrange on a serving platter. Arrange citrus segments on beets.
Whisk together vinegar, honey, zest, 1/2 teaspoon of the salt, and 1/4 teaspoon of the pepper in a small bowl. Add the oil in a slow, steady stream, whisking continuously, until emulsified. Drizzle vinaigrette over beets and citrus. Sprinkle with thyme and remaining 1/2 teaspoon salt and 1/4 teaspoon pepper. Serve at room temperature.