Wow, that's very colourful. I don't know much about Zerg, but I rather like the colour scheme: It's all function.
Yeah, the orange keys are the hotkeys on the command card that I use a lot or are zerg specific. the star )4) is my Queen hotkey, and the rest of the blue on the number row are my unit groups/building group hotkeys. the Green Bioharzard symbol (F) is for Fungal Growth/Build Infestors, and the Green Atom (v) is for larva inject.
To be honest though, I forgot the U, but that's for Ultralisks, and they are generally useless.