William Walker's weapons

[KraVseR]

I understand that this is not a forum about uniforms, but I don't know any else forums, where me can help.
I have a question about the uniforms of soldiers Walker. William himself was wearing the uniform of a black or dark blue. In this uniform were dressed and others filibusters in various scenes. Perhaps this form has some name? And how you think this form was worn by all filibusters or only the higher ranks of the army of Walker? And this soldiers in white dress - its Costa Rican army or filibusters?
https://upload.wikimedia.org/wikiped...res_Castro.jpg