So I noticed that the (non-recurring) demon character featured in Supernatural Season 11, Episode 15 ("Beyond the Mat") flashes his "demon" eye color for a moment in the middle of the episode. (To clarify, this is the blonde demon who's manipulating the WWE-type boxer.)
But instead of the usual "eyes turn completely black" gig, this demon's eyes turn red. This difference is never addressed in-episode or in the episodes directly following it. Granted, I haven't finished watching Season 11, but that seems like an awful long time to go without the show even acknowledging that something was different.
Does anybody have any idea why this particular demon had red eyes instead of black? Am I forgetting some demon backstory for the Supernatural universe that would explain this difference?