Paint is better, can't see how adhesive would look any good on the curves. It's a bit of a ballache doing the masking (1-2 hours masking, 10 seconds spraying per coat), but if you do it properly it's worth it. I used Halfords Tornado Red and it looked fine, nice and bright (just like Tornado red...).
It's supposed to be Mars Red on the 7-slat grilles, and Tornado Red on the 5-slats.
Here's how mine came out..
