#### Bug, feature request, or proposal: theming is right, but by default, snackbar with component, it is black color instead of light ( always on snackbar) #### What is the expected behavior? should be white or light #### What is the current behavior? on white light theme schema snackbar component is black/dark #### What are the steps to reproduce? it's easy, not needed to reproduce, just a custom theme, and snackbar component #### What is the use-case or motivation for changing an existing behavior? works #### Which versions of Angular, Material, OS, browsers are affected? all #### Is there anything else we should know? nope