Complex sentence: If damage is taken or mistakes are made, the colored fill area gradually reduces and leave behind a visible outline as empty, typically from one end to another, some also change color, typically from green to yellow to red as health is reduced.
Split into simpler sentences: If damage is taken or mistakes are made, the colored area gradually reduces and leaves behind a visible outline, typically from one end to another. Some also change color, typically from green to yellow to red as health is reduced.