well actually it wasn't a bad move for Prost, who was still trying to get some sponsorship deals at the moment of preseason testing. That way he could show how well the AP04 performed compared to any other car for the coming F1 season.
A pity Prost left, as the blue was also one of the better colours on the grid. Don't you think some teams really have "winning" colours. The lotus had it for instance (in de gold-leaf colours), Ferrari's got it, Renault is also such a team, yellow and white. And to give you something else... Toyota... oh my do I hope the'll find a new colour scheme soon! ... and Minardi, come on doesn't the painter got any ideas at all!??
BTW: a pic of the AP04