I understand what you are trying to say, it’d be more of degrading the users to make them feel sad because its at red, if the user was having hard time beating some challenges and never gotten the bar to turn orange or green, it’s sorta gives them higher hope rather just leaving the bar green. it will give no significant impact to the user if the color stayed green from 0 to 100.
I dont mean to flame. just my 2 cents, thinking it should be left green.