GREENSBORO, N.C. — Something exceedingly strange is happening at the John Edwards trial: all four alternate jurors dressed in red shirts Friday. They each wore bright yellow the day before.

   Coincidence? Few here think so.

   The demeanor of the alternate jurors and their behavior has become the talk of the courthouse. The alternates enter the courtroom each day giggling among themselves. One of the alternates, an attractive young woman, has been spotted smiling at Edwards and flipping her hair in what seems to some to be a flirtatious manner. On Friday, she wore a revealing red top with a single strap and an exposed right shoulder.

   Her actions have not gone unnoticed by courtroom observers, some of whom have chatted about her in increasingly anxious tones during the long stretches of down time while the jury, now in its sixth day of deliberations, meets behind closed doors to decide whether Edwards should be convicted on six campaign finance and conspiracy charges.

The case centers on nearly $1 million in payments from the heiress Rachel “Bunny” Mellon and the wealthy lawyer Fred Baron that prosecutors say was used to cover up Edwards’s affair with videographer Rielle Hunter and the child he fathered with her. 

   The alternate jurors play a supporting role in this drama. They watched the testimony, but will not vote on the verdict unless one of the 12 members of the main jury is removed. Two members of the jury also wore red tops on Friday. At times during breaks in deliberations, some jurors have gestured toward alternates, who sit at the opposite end of a small federal courtroom here that is packed each day with reporters awaiting a verdict.

   The sight of all four alternates in red drew titters from an audience that had already noted that Edwards had ended his streak of wearing a green tie to court for four straight days. NBC’s Lisa Myers asked Edwards whether he was wearing his lucky tie on Thursday, and he responded with a smile, “I’m not saying’.”

   The color he chose on Friday? You guessed it: red.