Did your babys eyes develop colour at a different rate?

My first sons eyes were always the same...started slate blue then turned light blue. My second born is now 4.5 months and I have noticed since he was about 2 months old that one eye is a bit different. I've seen people before who have two different coloured eyes but it isn't quite that dramatic. I also realize it's hard to tell at 4 - 5 months as the eye colour isn't permanent yet. Basically one eye is a darker slate blue still but has definitely lightened...its just more grayish and a lot darker. The right eye is a lighter and brighter blue. This isn't extremely noticeable but if I told you and you looked you would see for sure...