Back The Bid tube trains

Coming up through Monument station this morning, I saw one of the Circle Line trains that has been repainted in support of the Back The Bid campaign. The rear carriage was red and going forward from there the next was green, then black and yellow. I assume blue followed that but it was round the corner so I couldn't see it. Does anyone know what colour the front carriage is? Is it a mix of the five Olympic colours? White? Something completely different?

Anyway, given that London's tube trains are mostly a standard dull grey (apart from coloured doors etc.), it was a pleasant surprise to be greeted with a feast of colour alongside the platform. I say, keep them painted this way even after the bid has been won or lost. They could really brighten the tube up.