Problem with tab legibility on commit 7e541e59

On the commit https://git.drupalcode.org/project/bootstrap_barrio/-/commit/7e541e591bb... was include some styles for tabs, but they create some legibility problems.

1- The text of the tabs not active is the same of the nav.tabs ul

Example without color attribute:

2- When the tab is active there isn't contrast enough.

I think maybe will be better revert this commit.