Phrase 'red mist'

Hello,
could anybody explain the meaning of the phrase “red mist” to me? I found it in contexts like:
a) I was almost talked into accepting a year’s subscription to a video company before the red mist descended just in time and I slammed the phone down.
b) Husband faces life for ‘red mist’ murder.

Thanks in advance!

Try this link: Hope it will help – urbandictionary.com/define.php?term=red+mist

Red mist; meaning to become angry.