A particularly heavy flow of blood and sex juices coming out of a woman after she has sex on her menstrual period! The C stands for C#nt. Particularly gross when the man does not know that the woman is on her menstrual period.
John had sex with Betty when aunt flow was visiting and there was a C of Red when he pulled out.
A group of followers wearing red black and yellow symbolizing the Calgary Flames hockey team..the fans of the calgary flames in the stadium many fans wear the jersey regardless of playoffs hence C Of Red