Blend pinto beans, tomato sauce, and taco seasoning in a food processor until a paste forms.
Cook and stir pinto bean mixture in a skillet over medium heat until warmed, about 5 minutes.
Place tortillas on a plate and heat in microwave on high until warm, about 30 seconds. Spread warm pinto bean mixture, shredded lettuce, and Colby Jack cheese onto each warm tortilla. Roll the tortilla around the filling to form a burrito.