I think Natural red hair is absolutely gorgeous!!
As for the term "Ranga" I would never say it to someone, I'm naturally blonde and I use to hate the "blonde" comments.
But I can understand friendly jokes about it that involve no offense, but I don't think I would intentionally make such comment about someone's appearance.
I really don't understand what all the fuss is when it comes to Red hair..
I'm a hairdresser and people pay big $$$ to go bright red or have Copper hair like Nichole Kidman.. But if someone is naturally red it's seen as a laughing matter...
I adore natural red hair as it has so many high and low lights that no dye can fully replicate, and to be blessed with the complexion that comes with red hair.. I would die for that.