Is there a particular reason why ghouls' eyes are red? (called 'kakugan' based on my research).
There might be a reason provided by the writer, which I cannot research as it may only be available in Japanese. (I am thinking that it may be due to the color of blood?)
The kakugan are red due to the activation of RC cells in the ghoul's body. The RC cells are present in their bodies are when they activate them to use their kagune of due to them becoming excited, the kakugan activates as well.
A kakugan is an influence of activated Rc cells.
The kakugan are red as the RC cells are red in colour.
Rc cells (Red Child Cells) are certain cells that exist only in the story of Tokyo Ghoul. The origin of the name comes from how each individual cell looks like a curled up foetus.
