Eggs are white in color until the last moment before laying, when the hen puts the "bloom" on. The color or the bloom as it is called is basically a dye and each hen has different amounts of it in her glands. The more she lays, the lighter the color on the eggs becomes. If you are sure you have only one hen in this cage, it is possible she laid two eggs in one day, or laid before she had time to manufacture more "dye" and hence, the egg was laid white.
If you just want to sit them around and not open the shell you do not need to blow them at all. Just place in a safe place where air can get to them and the insides will dry out over time, be sure they are not too hot or they can burst if the rot inside. I have a glass jar full of my Button Quail eggs that I have just let air dry and the only thing is they are a bit hard to roll as the innards dry to one side so they kind of wobble. make cute wobblies if you glue on wiggly eyes. If you worry that they will rot and explode you can hard boil them first then let dry up.
Hiya, I get white eggs on occasion. As a previous poster has said, sometimes the quail use up all their pigment and so you'll get a white, blue or green egg. I've found it happens sometimes when a bird has been stressed but can also happen to my normal birds though I've found some do it more than others and it's often in the younger birds.
A female quail has her own "signature" on her eggs and if you save a few and compare, you will be able to see if you have two laying or just one. The patterns will never be exactly the same from one day to the next but will have similar blob patterns, blob colours, shell colours, size, shape and texture. I can tell who laid which egg in many of my pens, and the cool thing is it's inherited so I can often tell who the mum was of a young bird by looking at her egg patterns. I have a couple of strains with distinct "frosting" to their eggs and another strain with very large dark blotches. I find it awesome to see it being passed down