Hi Matt
This leaf is the only one i think to have such a bright red midrib. The midribs are usually a bone like brownish yellow that looks pretty good! As Mark said,various varieties can get red midribs for various reasons. Red midribs are said to be a sign of deficiency(i think Nitrogen but i dont remember well) too in some cases .
Also,remember that sun plays a huge role in color development and thus the same varieties can look very different depending on the environmental conditions. I can see the differences on my bananas too. They are much more colorful in certain periods and plainer on others,depending on the weather i think but i dont remember which periods make for the most color in Pyrgos. In Melissia,my potted bananas are most colorful during the heat and dry weather of the summer.
My ''Tall Orinoco'' hasnt pupped yet.