awtk/demos/assets/default/raw/styles/tab_top.xml

<tab_button_group1>
  <style name="highlight" border_color="#a0a0a0" fg_color="#1296db">
    <normal/>
  </style>
</tab_button_group1>

<tab_button>
  <style name="default" margin="4" bg_color="#eeeeee" border_color="#808080" border="bottom">
    <normal     text_color="black" />
    <pressed    text_color="black" />
    <over       text_color="black" />
    <normal_of_active text_color="#1296db" border_color="#1296db" border="bottom" border_width="2"/>
    <pressed_of_active text_color="#1296db" border_color="#1296db" border="bottom" border_width="2"/>
    <over_of_active    text_color="#1296db" border_color="#1296db" border="bottom" border_width="2"/>
  </style>
</tab_button>

<pages>
  <style name="at_top" border_color="#a0a0a0" border="bottom">
    <normal />
  </style>
</pages>