How do I make a y connector?
Red on White will toast receiver channels.
You can make all the Y's you want by splicing multiple wires off of a single connector, but be warned, you lose signal quality and this can make the servo's behave badly. It's EXTRMELY important that you solder whenever possible rather than crimp with Y connectors cleaner connection. And if your servo's don't have a reversing switch on them you can use a 'dumb cable' to Y like you want.