Not bugged. There are 4 color combinations for that ship. You can tell how many variations we have for each ship under its texture directory. This one has hull1-hull4, so there are 4 different color schemes. They are randomly assigned to the ship.
We also added an option to the original game, where you can pay the shipyarder to randomly “repaint” it, so that you get the option to randomly cycle through the various color schemes that might be available for that type of ship.