You could adjust the tabs via code – here’s an excerpt from my application, but you could also assign themes instead of the background image directly. (I haven’t used a way via xml attributes yet, not sure if that’s available as well somehow).
private void initTabs() {
tabs = (TabHost) findViewById(R.id.tabhost);
tabs.setup();
tabs.setBackgroundResource(R.drawable.bg_midgray);
TabHost.TabSpec spec;
// Location info
txtTabInfo = new TextView(this);
txtTabInfo.setText("INFO");
txtTabInfo.setPadding(0, 5, 0, 0);
txtTabInfo.setTextSize(11);
txtTabInfo.setBackgroundResource(R.drawable.bg_tab_left_active_right_inactive);
txtTabInfo.setTextColor(Color.DKGRAY);
txtTabInfo.setGravity(Gravity.CENTER_HORIZONTAL);
txtTabInfo.setHeight(39);
spec = tabs.newTabSpec("tabInfo");
spec.setContent(R.id.tabInfo);
spec.setIndicator(txtTabInfo);
tabs.addTab(spec);
...
}