Styel sheet Add / Remove / Override

Example :

# Add a new CSS file:
stylesheets:
  all:
    - layout.css

# Override an existing CSS file:
stylesheets-override:
  - system.theme.css

# Remove an existing CSS file: (Example : to remove barik colors.css file)
stylesheets-remove:
  - core/themes/bartik/css/colors.css