IE8 browser tab becomes a color what's going on

This is also one of the new Internet Explorer 8 features, called Tab groupings. When you open another tab from one of the page's midpoint links, the two tabs are divided into one group. The tabs for the same group are expressed in one color. This design is designed to avoid getting you in a lot of open web pages.

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I still like the original look, can I change back to the original look?

Quite simply, you can do this:

2. The Tools menu-> Internet options . (If the menu bar is not displayed, press the ALT key to appear)
   
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4. On the General tab, under the-> tab ,-> point settings .
   
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6. Remove the check in front of the Enable tab group (which requires Internet Explorer to be restarted) .
   
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8. Press two times to determine the exit Setup interface.
10. Turn off Internet Explorer and turn it back on.