I will relay a story about what recently occured to me, and another story that occurs every year for me.
The first story involoves a clutch off eggs that I cut about 2 weeks ago. I cut a clutch of 6 eggs from Cinny x Pastel. I cut them on day 50. I saw 3 Pastels and 3 Pewters. Boy was I excited. These would be our first Pewters, as we missed on them last year. They all emerged between day 57 and 58. What came out of the eggs was 3 Pastels and 3 Cinnys. It was amazing how much color they gained in the last week.
My second story involves hatching Axanthics. Over the last three years, we have hatched 7 clutches of Axanthics, with 3 more to go this year. Every clucth when I cut, I count the Axanthics, and every clutch, I always over count by 1 or 2. It is because in that last week, they develop into normals.
In essence, all I did was to agree with all of the precious posters that color is definitely majority aquired in the last week.