I recently tried to wire a ceiling rose which i had 2 black wires, 2 red wires and a single grey one.
What i done was i put the the black switch cable to the brown, the 2 red wires to the loop in block and the other black to the neutral also with the blue but im totaly lost on were to put this grey wire ive tried putting it with the neutral but when i swich on the back bedroom light the one in the landing comes on.
your boib to need to remove the switch plates then buzz these wires out with a continuity tester to try and work out what feeds what.
I think I can see what is happening with the cables you have (This is probably the last light on the lighting radial circuit) which explains why you don't have too many cables but I am confused by the bedroom light coming on. One of the reds shold be your live feed to the switch, they should go into the same block. one of the blacks is your switch live (should be sleeved with red or brown tag, but often isn't!) and connects to the live on your lamp. the other black is your neutral, but that leaves your grey wire. you don't have enough left for there to be 3 core feeding 2 way switching. can you see the grey disapearing into some grey or white insulation with some other cables or is it running as a single?
This is tricky without seeing it and being able to Buzz it out, don't know if KB can help, I think he's a bit more experienced than me in the layout of strange lighting set ups!!!
The grey wire is a single one but when i took the single switch off the grey wire is going from the common terminal then up to the rose.
Is it possible it might go with the black switch cable and put the brown lamp wire with the reds because ive tried putting the grey wire with the reds and getting no light but when its with neutral im getting some light.
But what happens is when i put the bedroom light on im getting full light in the landing and i bit dimmed in the bedroom the same with the toilet and in the back bedroom there is a little bit light.
mate, you've got issues!!
time to get a spark in I'm afraid. also that grey doesn't meet the regs if it's a single with only single insulation along it's length. sounds like you've got a major bodge on your hands there.