On Sunday, the Cowboys continued their early camp install, adding further refinements to the basic skills lessons that characterized the first three days' practices.
Sunday's practice opened with the defense filtering onto the field to get in some extra work on run fits while in the nickle defense. The guys playing offensive skill position players would don color-coded balaclavas, so the defensive guys would know who was playing which position (this affects their keys). They "offensive" players would look at a card held up by an assistant and then run (er, walk) the given play, with orange hats signifying receiver, red for tight ends and green for running backs.