I downloaded LibreOffice on my ArchLinux but it came with a horrible color scheme that is hard to discern from the buttons. I'm just wondering if there is any way to get a nice dark color?
It depends on what desktop environment or theme you are using. Please give that information in your question.
You can try changing the icon style of LibreOffice by going to Tools->Options->View and selecting a different icon style. If you are using the Breeze Dark theme in KDE Plasma you will need to to manually select the Breeze Dark icon style in LibreOffice since it'll automatically use the Breeze icon style not the Breeze Dark icon style.