WELL-HEELED For a few hours, until the NFL caught up with him, Deion Sanders stood out with custom Nike cleats. The white cross reflected his devoutness; 21 was his original number. (Neon now wears 37 on his jersey, a reference to his age.) But the league ruled that the number and the symbol violated uniform guidelines and had to go. No matter, said Deion, "I never wear the same shoe twice." He was back in the Ravens' standard white leather on Sunday and, without a cross by his Achilles' heel, left the game in the second quarter with a hamstring injury.