Brown Pelicans in Texas with dark, red and yellow/orange gular pouches in every combination with dark or white nape (that are considered as part of breeding or non-breeding plumages)

Here I have one more puzzle. According to some sources (e.g. The Cornell Lab of Ornithology: http://www.allaboutbirds.org/guide/brown_pelican/id) -

Brown Pelican - Adult breeding Pacific: Bright red throat pouch. White head tinged with yellow. Dark nape. Slaty gray body with darker belly.
Regional Differences
On the Pacific Coast, Brown Pelican adults have red skin on their throats in the breeding season. On the Atlantic and Gulf Coasts, Brown Pelicans are slightly smaller and their throat skin is greenish black.

So look here: in what is considered non-breeding plumage (white nape) one individual has red pouch (and also has bright blue iris).