How so i install a triple dimmer switch?

I would like to replace the triple dimmer switch in my living room. It controls 3 wall lights and one ceiling light. ther is also a single switch which controls the ceiling light. The wiring existing is mainly red with one blue and one yellow wire and the earth wire. The black wires have been joined to the earth wire???.

I labelled all of the wires and rewired the switch in the same way it was done previously but now i cant separate one wall light and the ceiling light. Also the unit hums very loudly!

Any help??