That's good info from Sherry. In addition, you want yellow on the bottoms of the feet of sumatra; green grass helps but feed with a yellow tint such as Purina's “Show Chow” or “Broiler Complete” has Tagetes = marigold extract. It not only helps intensify the yellow legs of American breeds like rocks & wyandottes, but it a great feed in general & helps intensify the yellow on the bottoms of sumatras feet. Yellow corn helps with yellowing, too, but it's only 7% protein vs. $20%+ starter or broiler feed. Summary- corn by itself isn't nearly good enough.
Realize when females have been laying for awhile, the yelllow will fade out, no matter what the feed.
No special feed is needed for the male's tail's; just good quality commercial feed; keep them with fresh, clean water as much as possible as previously mentioned and full feed. Sumatras don't get too fat like some larger breeds can.
Doug