Shamrock and Shanks

Shanks
Appearance
Shanks is one of the most recognizable characters in One Piece.
Its characteristics are:
Intense red hair.
Three scars above the left eye.
Dark eyes.
Light beard in some stages of history.
He usually wears an open white shirt, dark trousers, sandals, and a large black cape.
He lost his left arm saving Monkey D. Luffy when he was a child.
His presence inspires respect even when he is completely relaxed.
Personality
Shanks is very different from Shamrock.
It is characterized by being:
Cheerful and playful.
Very sociable.
Calm and patient.
Protector with his friends.
Charismatic and respected by allies and enemies.
Although he enjoys partying and drinking with his crew, he becomes incredibly serious when the situation demands it. He doesn't seek out unnecessary conflicts, but if someone threatens the people he cares about, he acts without hesitation.
He also stands out for his enormous emotional intelligence: he knows when to negotiate, when to withdraw, and when to fight.

Shamrock
Appearance
Shamrock is a tall, athletic man with an elegant and commanding presence. He bears a striking physical resemblance to Shanks, clearly indicating their relationship, but he has a much colder and more aristocratic air about him.
Its main features are:
Red hair, similar to Shanks'.
His face is very similar to his brother's, although with a much more serious expression.
Refined uniform befitting the God's Knights, with cape and details that reflect their high rank.
She always maintains an upright posture and an imposing presence.
Unlike Shanks, he doesn't usually show warm smiles or a relaxed attitude.
Personality
Shamrock conveys the image of someone:
Very serious and disciplined.
Cold and calculating.
Proud of his position.
Extremely loyal to the World Government.
Not very expressive and with great self-control.
He doesn't seem to let his emotions get the better of him and acts professionally even in tense situations. So far in the manga, he's portrayed as someone willing to fulfill his duty without hesitation.