To me, one of the prettiest Poecilia wingei is this; Poecilia wingei "Blue Neon", also known as "Emerald Green". Collected from Laguna de los Patos in 2006 by Armando Pou and linebred by fellow wingei enthusiast Shimpei Taniguchi. I am really happy to have these in my collection!
The green is different from the classic and well known "Lime Green". It is darker and deeper and depending on light it can be blueish too! Another thing that makes this strain so remarkable is that the females have almost solid black dorsals, something that is not common in Laguna de los Patos fish. Most males have white dorsals, but a few of mine actually have black dorsals. Perhaps a trait to line breed?
Typical male; black bar, deep green body with a bit of red. White dorsal.
Females have black dorsals.
Male with black dorsal and less black bar.
A bit of red in the dorsal too!