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I would say make the top bar the same or similar to the excellent title bars you've already got. Currently feels like they're from 2 different systems.
EDIT my personal preference is to colour the minimize maximize close buttons.
Other ideas: round the corners just a tiny bit. Make the dock look more like the taskbar maybe. See if there's examples from "Windows 95 Plus!" Which I think had extra themes.
EDIT 2: it looks great, you've done a good job here I like it!