Phlegm and Black Bile are confused?

I am curious why of the 4 Humors Black Bile and Phlegm are confused?
Wouldn't it make more sense if Phlegm was actually the Green Bar and Black Bile was the Black Bar? Since the Yellow Bile is the Yellow Bar and Red is Blood for new players this would make the most sense and not be as confusing as it is now.
Just my 2 cents...
Wouldn't it make more sense if Phlegm was actually the Green Bar and Black Bile was the Black Bar? Since the Yellow Bile is the Yellow Bar and Red is Blood for new players this would make the most sense and not be as confusing as it is now.

Just my 2 cents...