Two cables? Use the 10-to-16 pin cable. 10 pin connection to back of module, 16 pin connection to upper or lower power in 6U Rackbrute. You shouldn't have to worry about the red stripe (-12v). Both Behringer and the Rackbrutes use keyed headers so things will align naturally.
edit: I haven't seen the back of that Mix Seq so I'm assuming there is only one 10 pin connection.