The blocks it comes with are 2NO and 2NC blocks. 2 meaning 2 spots for two lines/wires. NO or normally open means the circuit is incomplete, NC means normally closed. The switches I assume are meant to control power to the contactor(s). Set switch to "ON" and power runs though the switch to the hot side of the coil to activate the contactor. You want NO here. No power to coil until it runs through the NO switch.
If you wanted something to be on while the other is off you can add the other NC block. As for the color just read the block (if you bought the switch) or read through the pdf. provided on the website.
I highly suggest reading through some of Kal's electric brewery site and learning about switches and other components. It really does help.