Philips Bluevision - Difference in light.

Hi everyone.

I just bought a set of Philips Bluevision H7 for my Fabia 1,9 TDI sport. I have the light version that just needs one H7 bulb for both dipped and main light.

Upon installation, I realized that the right light looked fabulous (visibly whiter, with a hint of blue), whereas the left looked very much like the stock lights. I then proceeded to swap the left bulb to the right and vice versa, and to my surprise, the right light still looked nice. So it's not the bulbs that are the problem.

I might be able to shoot a pic of it later when it's dark.

Any ideas?