I have a '66 Malibu I just had painted Marina Blue. I had already purchased from PUI a new Bright Blue interior. The color is real close to the color of the exterior. When I had the car painted I also had the interior painted Bright Blue. I got the color codes from DuPont. When I went to pick up the car the interior was almost silver with only the slightest hint of blue! After talking to DuPont again, the painter and the paint supplier we have determined that the color we used is in fact Bright Blue and what I wanted was probably Medium Bright Blue. So how come one company calls it Bright Blue and another calls it Medium Bright Blue? How about some consistency!
So my question is this. I can't stand what color the interior is now. It looks horrible with the Marina Blue exterior. I want to use the interior I have already purchased because it is the color I wanted in the first place. Is it actually Medium Bright Blue or Bright Blue? I need to get the correct matching interior paint, is it called Medium Bright Blue or Bright Blue? Is the correct Trim code for a Medium Bright Blue bucket seat interior 731? Does anyone have any paint numbers for Medium Bright Blue? I have asked these questions on many other Chevelle and Chevy sites and gotten no definite answers. I have run into several other people that have had the same thing happen to them. Someone out there has the correct answer.
Thank you very much!!  

Best thing you could do is to color match your interior paint to the exterior. That way there's no margin for error on having the correct interior paint.

You'll need to take a paint sample of your exterior color to the paint shop, and have them mix your interior paint based off this.