I've been told that it's still very hard to predict eyecolors because they are affected by a lot more alleles than fur colors for example. Some of them are linked to fur color (like siamese points&blue eyes and burmese points&yellow eyes).
It's very hard to get a good green eyecolor, and I'm now talking about a pure green, not any mixed yellow-brownish-green. I have cats with green, blue and 'tarnished' yellow eyecolors, and both of the yellow eyed cats have green eyed daddy and a bad green or yellow eyed mother. Sometimes breeders mix pointed cats (blue eyes) to green eyes to make the green better, which seems to work, but yellow will ruin it completely. If you know what you are looking at, you will know around 12weeks if the kitten will have green eyes but it takes a lot of time for green to get to it's 'final stage'.
Kuura 12weeks old, clearly getting nice green eyes
And last summer at the age of 2 years, still a bit too pale color but clearly green
Kuura's son Tomu at the age of 14 weeks, yellowish eyes
And mixed yellow eyes at the age of 7 months