Have look at the Uniqlo dry pique polos as well. They look like normal pique polos, so you can easily where them off the course as well, but they also have some kind of tech built in to make them dry faster/keep moisture away from your body.
I have a few light colored ones for play in warm weather.
At 15 GBP apiece, they are really cheap compared to most "high-tech" golf shirts.