Does a highly visible frame colour improve safety significantly? Studies have shown that wearing hi-viz colours, particularly on moving extremities such as one's feet, coupled with hi-viz helmets and cycling shirts, increases the chance of been seen by a driver from a safe distance. The same principle also applies for reflective clothing at night. Flashing lights, also dramatically increase the chances of being seen by the driver of an approaching vehicle.
Does having a bicycle frame in a bright colour also dramatically reduce the probability of being hit by a vehicle?
(To provide a bit of context I am contemplating buying a new road bike and the model I am eyeing comes standard in black. For an additional fee I can have a custom paint job done, but I am questioning whether it is worth it. Given that I will be using the bicycle mainly in the country side, and not in cities, I am expecting fast moving, but not very dense traffic, and few intersections. I am most worried about the cars over-taking me from the rear.)
It wouldn’t make much difference from the rear. All a driver could see from the rear is the top of your seat stays, which aren’t very large. Same goes for the front. From the side, it would make more of a difference, but I wouldn’t say it’s significant enough to justify the fancy paint job.
Of course, if you like the way the fancy paint looks as well, that might make it justifiable.