Took this image last night, wth the 6 inch "Cometracker 6 inch f3.6 schmidt newt.
2x5 mins ISO200, no filters at all. Hutech modded 350D. Full res. crop of centre of image.
During processing I used the colour stretch function of Iris to bring out star colours. Theres a pile of brighter yellowish stars, some white ones and a lot of fainter blue ones. "Blue stragglers" perhaps. They are explained here
http://www.solstation.com/x-objects/bluestrag.htm
Scott