i think specifically ginger is usually meant for people with carrot orange coloured hair but it's inevitable and true that any person with any shade of red hair will be/is called a ginger. basically born a read-head (regardless of shade) = called a ginger i think it's just an easier blanket-term since basically every red-head has a different name for their colour (how many times have you heard someone say "it's not red- it's strawberry-blonde!!) (this is mostly because ginger usually has negative connotations)


a pointless but fun fact
a couple years back the term "ranga" (as in orangutang) got popular in australia as a term for red-heads. didn't matter what shade (even though it was intended for carrot orange coloured hair) every person with red hair was called a ranga. it's not really used anymore though.