The mini ISO connectors are the blue, green and yellow blocks. As they all control peripheral featuress that aren't critical to the basic function of the stereo, you are right in saying that if you can fit the black and white connectors to matching sockets on the new head unit, you should be good to go.
It's possible that some of the finer points of power management (like, for example, being able to turn the radio on/off when the ignition isn't on) may not work as expected because the way the various pins are wired up can vary a little from one manufacturer to another.