I donẗ know why, but Terminal panel color is from dark theme, but everything else follow standard gray/silver color. How to fix this?
edit: I found that Videos media player is also dark. Is elementary OS theme broken?
This is normal, probably it's chosen where it was deemed appropriate. For example a darker border around a Video is less "distracting". Daniel Foré is working on a light theme for Terminal: https://www.youtube.com/watch?v=wOAlqsA0XF0
Not sure why such choices aren't covered in the Human Interface Guidelines