That's definitely occured to me during the rewatch I'm doing. It seems strange that the Maquis get uniforms, while Neelix and Kes don't. I get that the Maquis crew had already signed up to serve on a starship and take orders, while Neelix prefered more autonomy, but after the first year or so the two of them are absolutely part of the crew same as anyone else. Season 3's Fair Trade seems like the ideal point for Neelix to switch to a uniform.