FYI, only the "captain", or the person in charge of each ship, wears white panels. But:
1. Not all "captains" are of rank Taisa (Captain). Only the big, bad battleships get Taisas. The smaller ships are captained by lower ranking officers. A Ketsueki gunboat, for example, can be even captained by a Taii, who would wear white-panels in that position. (!)
2. Aurore, a fleet admiral, is technically NOT the captain of the Celia, even though she's obviously the highest ranking officer aboard. Yuri, with a rank of Chusa (Commander), is the captain, and is in charge of running the ship. Aurore, meanwhile, is in charge of running the entire fleet. As a special case, Aurore also gets to wear white panels alongside Yuri.
Confusing as heck, I know. ^_^;
I'm pretty sure we got these conventions from real world navies, so you can't blame the GMs for this one.