From a seed batch of Liberty Co. FL S.flava var rubricorpora came an intriguing specimen.
As can be seen in the photos where it is among other clones from the same batch that are representative of the colour range of the variety, including some very dark ones, the plant in question has a orange/pink hue to it. The pitchers are a bright, glowing yellow (almost too bright for photo's exposure balance) when first open with the orange/pink beginning to show mid-tube (see smaller pitcher in centre). There is a slight pale shading on the outer margins of the column seen only as the pitcher matures, but no real S.flava var rubricorpora/rugelii splotch to speak of. Equally, there is no distinct colouration to the venation.
The result of intergrade pollination between var rugelii and var rubricorpora (obviously this occurs)? Distant past hybridising between flava and purpurea venosa as a component of the current clone? Or, a random colour phenotype?
The collector of the seed has made many visits to the Liberty Co./Apalachicola S.flava range and, despite encountering the spectrum of colours that exists within var rubricorpora, has personally never observed just such a plant in the wild populations.
That's very interesting. The yellow is probably the brightest I've ever seen on any Sarracenia leaf. Liberty County seems to be full of gems. Bill Sholl collected a S. leucophylla from the same county some years ago and it's by far the most impressive form of the species I've ever seen. The opening is twice as wide as any other leuco I can think of.
It's possible that it could have back crossed from a S. x catesbaei decades ago, thus resulting in what you're seeing, but we'll probably never know. One thing we can be sure of is that you have a stunning plant on your hands.