Thanks for the feedback! The gadget's status indicator should go from green to yellow to red as the value passes from normal into warning into critical. Is this what you're seeing? If you look at the screenshot, the left gauge is in warning state, which causes the gauge gadget's status to go into warning (the yellow globe icon), which bubbles up to the tab. When you have multiple gadgets on multiple tabs, it makes the tabs tree on the left a quick and easy way to discover what went wrong.
Are you saying that the threshold status should be more "bold" on the gauge itself when in warning or critical state? I want to make sure I understand what you're asking.