Slitherine

When v1.8.3 was published in July last year one of the new features was:

Changes:
 Custom camouflage skins to personalize your ground vehicles

In fact, under \Documents\My Games\Order of Battle - Pacific there is a Skins folder. Unfortunately I couldn't find info anywhere how this feature works, which image file formats or sizes are accepted or how it works in the game.

Does anyone know more?