Using tabs is sometimes a very good option for a wed design. Visitors use them to navigate the site and to know where they are.

The JCPenney tab rows are 100% fine. They use a different color for the selected tab, but this color is similar to the one used for the unselected tabs. From the usability point of view, I can imagine that this could affect visually impaired and color blinded people.

Giving users a graphical and shaped sign could be much better for everybody. The MySQL website not only uses a different color for the selected tab but also makes a connection to the menu line below, creating a much obvious and nicer visual effect.