It's an interesting question, but be prepared for the possibility that there will be nothing significant to report. But any differences in the suggested questions below might lead to some conclusions about why producers choose one kind over the other. Frankly, I don't have a clue what the answer is. The following are just suggestions, but you can see where I'm going with this. Don't be stopped cold by a simple "no":
If there is a chemical difference in the shells, you might have fun talking with chemists or food specialists to see if there is a simple test that can be done that shows the chemical difference in a clear way.
Beige is beige and brown is brown simples
The difference between them is that white fat is found in adults and brown fat is found in children.
All of the different colours seem to be the difference between the grey, white and brown mice...
One is brown and the other is white.
Gordon brown
Ones Brown and one isnt
The differences between a red and brown ladybug is the coloring. Although, the ladybugs are different species there isn't a big difference in the bug itself.
the color
There is no differrence .
Brown dwarfs are more massive than the planet Jupiter.
ones brown ones white
Brunette is a little bit lighter than brown.