In The Wizard of Oz, Dorothy dreamed of somewhere over the rainbow. Thanks to color throws that leave joggers covered in blue, yellow, orange and pink pigments, entrants in the Color Run may feel as if they’ve found that magical place. Billed as the “happiest 5K on the planet,” this annual gallop is more about having fun than winning a race — the 3.1-mile jaunt is untimed and open to folks of all fitness levels. This year’s theme is “The Color Run Dream World Tour,” so runners can expect to find giant unicorns, a cloud-like foam zone and a dream wall where participants can proclaim their aspirations in spray paint. Proceeds benefit Chill Burlington.