If you have nothing to declare which customs channel should you enter as an eu citizen?

For Customs purposes, when entering the UK, it is really more to do with where you have just travelled from (i.e. from within the EU or otside of the EU) rather than whether you are a EU citizen or not. If an EU citizen journies to the UK from say, the US, Nigeria or China etc etc, then when they go through Customs they will still have to make the decision to enter either the Red (Something to Declare) or Green (Nothing to Declare) channels. It has nothing to do with being a EU citizen. Likewise, a resident and passport holder of say, Mexico who has left the UK mid holiday for a day trip to France will have to go through the Blue channel (EU travellers). Earlier posters may have been confused with the EU citizens and non EU citizens queues at Immigration entry points at UK ports and airports. In the future, supposedly the twin Customs/Immigration entry points will be a thing of the past with the creation of the UKBA (UK Border Agency) and the single point of entry.