Good pick Tom - yes what you see is a double star - two components (A and B) much the same colour and magnitudes to our eyes. The flashes of colour is because of refraction thought the large air column - they are are quite low elevation at the moment - try again in some months.
Now the challenge, to try and find the third star in that system - Proxima Centauri - quite faint and well separated from the A and B stars - but, at the moment, the closest star to our solar system.
http://en.wikipedia.org/wiki/Alpha_Centauri