Railcard is a Honkai: Star Rail character showcase cards maker. It uses Python (v3.12) and powered by mihomo. Yes it supports custom images. Yes it indicates relic rarity with the background color.
For the Discord bot version, check https://github.com/yuvlian/railgen.
To get started, run terminal as admin and type these in:
git clone https://github.com/yuvlian/railcard.git
cd railcard
pip install -r requirements.txt
python main.py
You can also get the prebuilt instead if you don't want to do any of the steps above. Extract the zip and you're ready to go.
(This one is generated with an older version, it is here to showcase the handling of no LC and no relics.)