i believe, may be wrong, but the kona has a gold and red metallic flake, where DIB may be just the normal metallic flake. This is something that Mazda used to do metallic colors. Always created a little different pop. After the tsunami in Japan, some of those colors were limited/harder to come by due to the metallic flake. There is probably difference in hue, but the flakes may make it appear even more so in the sun.
You're wrong. Sort of.
Kona uses a special type of fleck or flake in the paint. Same with the Tuxedo Black and Lava Red. The flakes in Kona Blue are Xirallic flakes, produced at a company in Japan which was damaged in the earthquake and tsunami last year.
Xirallic flakes create their color via a prismatic effect. The color the flake reflects depends on the thickness of the flake, assuming white light is being reflected.
Because it is a prismatic effect, if the light source is heavily shifted to the red side of the spectrum then the color reflected back will be purple rather than blue. Likewise using flakes of slightly different thicknesses can reflect back different colors in the same lighting, as was commonly seen on Tuxedo Black.
Deep Impact Blue does not use the Xirallic flakes in the paint, which is why it doesn't have the ability to fade to a near black or appear purple like Kona does. It's going to look blue in every light because it uses a traditional silver colored metallic flake embedded in the blue paint.