It's just the way the light is hitting the car. White is REALLY hard color to shoot digitally without blowing out the whites or making things look strange. It's just the nature of the color.
Moto's spoiler matches his car perfectly, but your skirts definitely look a bit off in the photos. The key though is this picture:
If you look at the way the light is hitting the front bumper you can see that the paints look a bit different. It might be a different type of clear coat, or something else that's throwing off the light.
Here is Moto's spoiler:
Here is a black Five-Axis:
The reflections match up. So my guess is that there is a difference either in the pearl or clear coat on your kit that reflect light a bit differently, so it'll be hard to shoot photos of since digital cameras are super sensitive to stuff like this.