All the green/yellows are earth. Two of the reds are the loop in and out phase lives. Two of the Blacks are phase neutral loop in and out. One of the reds goes to your wall switch and one of the blacks is the switched live back from the switch and should have a sleeve.
Connect earth from your light fitting to the earths. Connect the Neutral to the neutrals. Connect the live to the switched live.
If you do not understand any part of this, get an electrician before you kill some one or burn your house down.
t, May 2008