Blue is definitely the safer, more classic choice hard to go wrong with it. It really comes down to personality though… whether you want something more subtle or something that stands out a bit more.
I put together a quick mockup to help visualize a few directions.
Personally, I'm leaning toward the darker blue it gives the car a more aggressive, refined look. COBRA COLORS.jpg
If my color choice was blue, I'd go with Ferrari Avio Blue. A friend (8secondDuster) painted his coupe that color and it's spectacular in the sunlight. The amount of "flop" as the lighting changes is incredible.
Here's what I believe is the Hydro Blue Pearl on a Cobra. While I do like the Royal blue, I'm wanting something a little different. My daughter and I are leaning towards the Snake Skin Green, and my wife and son are leaning towards the Hydro Blue Pearl.