light won't go off?

Just fixed new ceiling light in kitchen diagram in box for fitting plastic connection already on ceiling so the wires on the light were 2 red 2 blue so joined the 2 red and the then the 2 blue together and inserted them into the same opposite holes on the connector I think is right does not seem to be anywhere to put earth connections but when I tried the light it won't turn off what have I done wrong the old light was working ok
hope you can help
thanks