So I did a mockup of some uniforms using a character creator. These are what's ISSUED to those who become full-fledged Blackshirts, though modifications/customization is welcome to the field uniforms, such as adding a helmet if you have one.
[hider=Infantry Uniform]
[img]https://lh3.googleusercontent.com/vsHuMbD5iCjo0LO74KSIAwk4NnShMmRcCD7ZBPgLOL_63rP04Fl8EtZOM4mHyP3uPY9vwpS8SLG6s3w1sBlwt8vQAwUz2Z0R7vLamlr7LJxW-QWww0W7XK5dfqf23ISpH0dkloaqnMfq25b0AUpbzdiHe8-LE3kUsmNl_bs5LIDPDNaRw6-CQAUgwLcxANAkxA5dlTOhY9nz8O5mCpHlVbBRHswqC8ZuEfTj9DYC1c2lyozljZ_gOUC5CObykaw2a3jNmLcW3etWXUoAXYugj6cCg7N1zgcm9JgyrX9al8YOHx9ZXthPpP9bNBV0hoY-maaHqYrxQiQrhRUCO9gqKh-Has5utkeORHpt8XAhIN68reduVn-I0ZRhdN9FAYCBPCD8UhZ5oUUkYFTRsjajrz4HN2pcy2B9qDLDdBVzRbRJbGwK6x_6Nf8VsDun66dgR_2MiVNN5NvV9815K-MRNJDl-6Tx942Qmbg0i7J0vvhxn5RPDW5A2sMe_juULhj2sDIn_wzb3wcbWEMmS9kvykuCvRiau_JhF2AZuwNyVuQd3pALD09bW6f6kioWi_VKHf3Vlfru=w1366-h580[/img]
The Standard Blackshirts uniform consists of a khaki undershirt worn with a cloth field shirt and pants, and black leather boots. A green armband emblazoned with an Iron Cross is the identifying marker, worn on the left sleeve. A black beret is issued as standard, as is a y-belt with pouches designed to hold M1895 en-bloc clips.
[/hider]

[hider=Cavalry Uniform]
[img]https://lh3.googleusercontent.com/TiRHN9V-HXtzhCNI3NmPqyeNZ0CJ8Eo0_w4oyFn4MbV5FpzZFmN3669E5-zYs5QOjLQa2Yu4UJQmH2E6BhdbBH-GylN_MYV9aF0_-1gRec0zBXBtaHuJz1wOumujJkmrd9MRRcsTSvJ5Kwc-nBr7dWYhWG9R1nL3hpohlNAgBf21JsRNYQcRePehFlUcm13j1zKyKN8kgYbA07Tijd4L4GJOvhr9rJN3AemkYVbFX2c9qjBsYlBPhErELsf0jfspP3qpBnRQrpsjq2raNmwGHF6L4Hho8lXlcz7n8OsbJFGtT05zHZb_A3FD8ETk-ONEgpT9XQA55PvScZRzLx_o73ZhYSg4a_uuMpTopPngVFQiBjReCx4vNNNOAozNN1sIrgthPIlpVqhL03AN5ivYB1XktUybMiYJcL6IeOwAW03Ur4HhPjBITNQiWRG94cjwYGltqCIRVOYmIsH0jDmJATXYxPI8RQvI6adnF9iOHvksMXxDmKhdHFi9Iiq7w_VX7nhbCM9gNbfakSuK2ME2pzQF2pIDO_bMGx4j5Fm9SspIwc5ofbeW4KABuft--hm8U3e4NZM3=w1366-h580[/img]
The cavalry uniform is fairly similar to the infantry uniform, though with a field cavalry coat instead of an overshirt, and a peaked cap in place of the beret.
[/hider]

[hider=Winter Uniform]
[img]https://lh3.googleusercontent.com/40tldNxnuyJkPmckmUxfmBw8MtcXJip5-gwUe7buy8-T6x57hVZlLDQH5mRtRCQzFJLGI-7Ke2sgCtIh0HuDsCOLxqTifRqS5cB7QN3OATgZujdFI9ZzT-_xok9bvWhfJUOPZT1R9gxzVl6aOEh-Y4kbrGKnjdtYMCmp9-UukETdvGGRp_PS7kVkuHp47FS3QJJ4wcW7M_mWRfH7YwrxrRaH0gKbea1Z66jaOWnHHFJHIex6UAd_jvQmqGf7bicH8WMEmV8-cS8cgv_IUDU163lRlOVMjCKMDHL3Rfe9llx8BkWYfTG5BpO2OEXw35MSGZLNjRRlXYaBaMNxGx_6F8xEvSWY6aDIFdVzXIgYzHWpaPUGhpsT0cQn6whuPADdx1SYsCSgyTIkfTTbmzUnouEf7tfYvXIsu1UkF5IiQXHVANlKfO3YowcYfMBcMfgMuIAE_OFN6B5HVBY_71mbCmIFeHnEDbwD4aq-IqazK6im-UWOvqwICvSjJGiggZ3skDYuY5AIcX9I8IJ2bBvGqENHY9qv4d3AJiw2MK8TgAOMknqX3sIwM7BCBodJL3sj2HRa37ZO=w1366-h580[/img]
In the winter months, everyone is issued a khaki scarf to cover the mouth and neck, as well as a winter cap made of thick fur and cloth. The infantry are issued black greatcoats, still bearing the identifying armband on the left sleeve. The cavalry receive a thicker cavalry coat, which is designed to be shorter than the infantry greatcoat, so as to not impede the rider, while still allowing for protection from the cold. Thick wool gloves are also issued to everyone.
[/hider]

In parade and marches, uniforms are expected to have any modification beyond helmets removed.