I know this post has been up for a few months but since there have been no replies I wanted to add what I have used. I have been using a 16GB SanDisk Ultra 30MB/s SD Card with PwnPi 3.0 and so far no issues at all. Colors are fine, commands execute with no issues, etc. You can expand the file system to the full size of the card as well as you can see in the screenshot of the OS screen.