Hi Raelgrin, Dont connect wires as in your answer, you will trip the breaker in your fuse box, the only neutral wire is the black, consider the two reds, the blue and yellow as live, why it did'nt trip / blow / fuse, in your last attempt was because you isolated the yellow with the red sleeve in what you call the spare. When you get cables with red, yellow and blue coloured wires you have normally two way switching ie. more than one light switch, before attempting any connections make sure the supply is off at fuse board double check this with other lights in building, how i would have connected it up but please note it might not be right? the two reds have to go together if you spare hole in the new fitting is not a second earth block / terminal and is isolated from the earth connection put them in there. Otherwise join them in a connector block and tape up, The yellow with the small red sleevind would indictate to me its the return live feed from a switch this goes to L of the fitting. if that dos'nt work let me know i would need to know some more information from you,, kind regards red-forest.