The Yellow in this spiritual portrait represents Tywin's dominant trait, his pragmatism. In Introverts, the dominant trait is directed inwardly, and spiritual portraits use a long horizontal line to represent this. He demonstrates this trait in his down-to-earth manner and attention to business.
The Green in this spiritual portrait represents Tywin's auxiliary trait, his preference for making logical rather than emotional decisions. In Introverts, the auxiliary trait is directed outwardly, and spiritual portraits use a vertical line to represent this, because it is more evident than the dominant function. He demonstrates this trait in his the way he treats people, including his children without any hint of emotion.
Lord of Casterly Rock
Tywin Lannister's personality is extreme, and his spiritual portrait ....
Tywin Lannister's personality is extreme, and his spiritual portrait reflects that.
Tywin's personality (and spiritual portrait) is almost identical to Stannis Baratheon's. This is because both characters are almost completely closed off to all Perceptions — as indicated by the extremely small quantities of Yellow and Blue.
The Lannisters are wealthy, and it's natural to assume that his children are pampered and spoiled. In scene after scene we realize, nothing could be further from the truth!
As an Introvert, he doesn't volunteer much without prompting. When people come to him, however, they get an immediate, honest, and direct response.
The house that puts family first will always defeat the house that puts the whims and wishes of its sons and daughters first. A good man does everything in his power to better his family's position, regardless of his own selfish desires.
On the commentary tracks at least one commentator — and I believe I heard this sentiment more than once — mentions that due to the extremely closed-minded nature of the character he plays, the other cast members are actually afraid to approach Charles Dance off the set. Any viewer of the show can certainly understand this reluctance!