[Imperial officer cape]

I was under the impression that they were line officers and their uniforms are soaked in the rain, thus causing them to appear black.

[Suggestions needed for Imperial Officer costume]

I'm in the process of building my Staff Officer costume as well. I bit the bullet and ordered a costume with Magnoli Clothiers. Yes, they are expensive, but they custom tailor your uniform. They ask for exact measurements, so you aren't just ordering a small, medium or large. I only ordered my costume last week, and I don't expect it to arrive til early October. Hopefully they live up to their reputation!

 

Magnoli doesn't make hats, but you can ask for an extra yard of fabric and find a maker here in the forum. I bought my hat from Disney and actually looks pretty good! 501st approved too, if I believe.