How do I wire bathroom spotlights?

I am trying to replace/connect two spotlights and a switch mounted on a board in my bathroom. There are two sets of 3 wires coming out of the wall, blue brown and green. I assume one set feeds power in and one set takes power out to the next switch in the circuit? The spotlights themselves also have a brown and a blue wire coming out. So I have 8 wires in total - 3 brown, 3 blue and 2 green which I assume all need to be wired to three connectors in the switch? I have tried a couple of combinations but can only get to the stage where the lights come on but as soon as I turn them off all the lights in the house go off as the lights main fuse is tripped. What am I doing wrong?