The purple outline is another extravagant luxury; being the darkest colour purple should only be used for the darkest shadows, as you cannot afford outlines that are wider than what they outline.
Is it necessarily "wrong" to have a double outline? Can't areas of solid color indicate the deepest shadows?
That's what I said. There is good purple, in the deepest shadows, and bad purple, in gratuitous outlines all around the outside border and the interior.
I don't think this piece has enough room for outlines, let alone double ones; if you really feel they are needed, you should restrict them to the exterior silhouette and make them consistent (currently the outline has large gaps in the upper left portion and inconsistent thickness in many places).
The third revision cleans up some little defects and adds about the same number, but the cluttered overall design got slightly worse: the top orange portion has a new blue bar and blue dots that, together with the preexisting diagonal of blue dots, suggest a fluorescent tropical fish rather than a machine.
What's the rationale of the orange/blue colour combination in general? Real world ships have the "natural" appearance of their materials or a principled paint job, not such arbitrary patterns.
