Pour boiling water over tomato sprinkles in a small bowl; let stand 10 minutes or until soft. Drain in a colander over a 1- cup glass measure, reserving liquid. If necessary, add water to reserved liquid to measure 1 cup; reheat liquid to 120° to 130°.
Combine contents of hot roll mix and enclosed yeast packet in a large bowl; stir well. Add very warm reserved liquid, tomato sprinkles, butter, egg, and feta, stirring until dough pulls away from sides of bowl. Turn dough out onto a lightly floured surface; knead dough 2 minutes or until smooth and elastic. Place bowl over dough to cover; let rest 5 minutes.
Divide dough into 16 equal portions, shaping each portion into a ball. Place on a baking sheet coated with cooking spray. Cover and let rise in a warm place (85°), free from drafts, 15 minutes or until doubled in bulk.
Preheat oven to 375°.
Bake at 375° for 19 minutes or until lightly browned.