Hopefully one of these can be useful to you. These are just names I would have possibly chosen for these guys. I also included some pair names for you. As I have a twin myself and our parents happened to make our name a pair one.
Colt - Barn Names: Donovan, Xerxies, Beau, Noir, Cole and Liam. Show Names: Black Berry, Black Tide, Day by Day, Dream Catcher, Believe n' Miracles and Valley Whisper.
Filly - Barn Names: Tart, Sugar, Fiona, Patch/Patches, Hope and JJ. Show Names: Red Oak, Red Rum, Morning to Dusk, Sunset Sunsation, A Dusting of Gold, and Fine n' Dandy.