Definitely blue. We are the same as drivers in any other industry (road, rail etc.). It's just that our licences cost considerably more to get and when we foul up, the results are very widely broadcast. We also put our nads in the line on a regular basis (checks, training, medical) and have very expensive equipment to look after. In return, we are generally able to change more for our labour than most other blue collar workers. Just so long as not too many muppets are prepared to work for nothing!