In regards to the "flashy things get stolen" idea...

I've seen a lot of "BIKE STOLEN: HELP" type posts around my city on CraigsList, local bike blogs, etc. And there doesn't seem to be a theme of whats targeted. It appears as though there are just as many $150 beater mountain bikes stolen as high-end roadies . Now - there are a lot of ways to read into that...

-Even though i've seen a lot , its a small sample size - even for my city as a whole.
-Perhaps the guys riding the "beaters" are less vigilant about locking/protecting their bikes and that inflates the amount of that type stolen.

Just food for thought : if you go with a "loud" color scheme, not only is it going to stick out more on a bike rack, its going to appeal to a younger crowd. Both of which will improve your chances of it getting stolen, in my opinion.