When Jack first meets Lureen - when she rides by and sheds her red hat, who is in the background but a cowboy wearing a black hat and a red shirt, to her black scarf and red hat. He is the black-hatted cowboy she should have picked that night - her diametric opposite.
By choosing Jack, she seems to be rebelling against what would be a more natural choice for her. Jack is not college-educated, no steady career track, driving his horrible old truck around the rodeo circuit, etc.
But then again, Lureen is not a typical girl of the time. She wants the Newsome birthright, not a husband who will take it over for himself (as a typical Texas macho man might). Was she consciously thinking of this when she approached Jack? No. I think during their dance, it's obvious that she's falling hard! But one's subconscious is hard at work during moments like this. Jack picked her hat up for her, but would not approach her at the bar; in other words, he's helpful, but not a take-over type — just what Lureen needs.
So even though her father disapproved of her choice (and others in her sphere probably scratched their heads too), she knew what she was doing in terms of her long-term plans. (Although emotionally, it was ultimately a disaster for her.)
On the symbolic/color level, it struck me for the first time last night how Lureen's introduction immediately follows the fireworks scene. You have Ennis kicking ass, fireworks exploding in the sky... cut to red-clad Lureen exploding out of the gate.