I realize that brown or blue eggs may get paler as the laying season progresses, but today I found a white egg in the nest box. It was small, like the Sussex girls lay, but pure white, not brown. Strange.
Dew found a white egg (not laid by Miss Prissy) a couple of weeks ago. If you put it next to one of Prissy's eggs, you could just see the slightest tint, but by itself, it sure looked white. I think it's one of the Australorps that lays very light brown eggs, but Dew would know better than me.
The brown gets laid on the shell last. Think of it as a white car going through a paint shop. The topcoat is sprayed on last.
If the hen laid the egg early, say something scared her while she was on the nest, she may have laid it before she had a chance to spray on her normal brown. I've got a few of those, not many but it is real noticeable.
My Speckled Susses' lay a light tan, almost pink egg. As the season goes, it will get lighter and lighter until I have to put it next to something white to see the color.
Consider it a bonus - more variety to your egg basket.