I've been playing VO for a few months, and gotten used to its normal HUD setting on Android.
After downloading "Greyscale" skin, the HUD's suddenly nothing but white.
I removed "Greyscale" from the plugin list,and it's still white.
Mind telling me how this happened? Thanks.

I don't know what you mean about the plugin list. Skins aren't plugins. If you were using a plugin to manage your skins, maybe that plugin is glitchy and didn't unset the skin correctly? That would be a matter to take up with the plugin developer.

Anyway, check your config.ini file and look for a line that starts with skin= (it should be under the [Vendetta] line). Delete that and try starting the game. If you think you already did this, try it again -- maybe there was a duplicate entry. And make sure the game isn't running while you edit the file.