Manhwa with a female lead who keeps dying by the age of 25 and reincarnating to start over again

Question

At the beginning, it showed a red-haired woman who was dying. Then she was in front of a man who greeted her familiarly and said something like "so you're here again?" because she died. I'm pretty sure he had red hair too but I don't know.

It's then revealed that she has died five times prior, all of them before her 25th birthday. He then gives her an amulet with four stones in it and explains what they're used for, except for the last one, because she eats the sweet-like reincarnation stone.

She is reborn in the same world as before, as per their deal, but she is reborn as a noblewoman with white hair and striking green eyes. But because she wants to be able to protect herself and live past 25, she eats the stone that allows her to become whatever she dreams to become a knight and gain strength.

She finds a blond man in the middle of the woods who is very hurt and she uses the stone that cures all diseases. The man turns out to be the son of the king or emperor . She also uses a magic sword thing in the middle of a tournament. Also the royal family has blond hair, if that helps.

Answer 1

Is this The Lady's Law of Survival...?

“Please let me take over someone else’s body this time!” That was my request to the King of the Underworld upon my latest arrival. None of my previous incarnations made it past my 25th birthday, so the king promised that if I succeeded, he’ll grant me a long, healthy life. I asked for an existence filled with wealth and physical prowess that had no siblings and no complications with men… At least he fulfilled the first three! My name’s Lukina. Title: the Duke’s daughter. And my goal: survive past the age of 25!

The opening chapter seems to fit your description, with the female lead (who initially has orange hair) dying after being poisoned by her half-sibling and appearing in front of Yeomra, the red-haired King of the Underworld.

She asks why she keeps dying before her 25th birthday, and she's apparently sick of it, so instead of being reincarnated again, she asks to be transmigrated as a woman who is beautiful, innocent, has enough basic physical strength, and no half-siblings. Yeomra says that there's one woman who fulfills those requirements, and that woman happens to have white hair and green eyes.

Before transmigrating her into her new body, Yeomra gives her an amulet with four different-coloured jewels in it, and she swallows the golden one. Right after that, she transmigrates and wakes up in her new body.