Female characters from A Song of Ice and Fire with roses because that series is all about the War of Roses and because the female characters are awesome. Have some thought process (if it's incorrect, blame the internet):
Cersei Lannister: Yellow roses are for happiness, so she's destroying hers, lol. (I'd like to think she's pretending to crush house Tyrell.)
Sansa Stark: Pink roses are for admiration and sympathy. You gotta respect the crap Sansa is able to overcome.
Arya Stark: Blue roses... I'm pretty sure aren't real, naturally, haha. But they symbolize Lyanna Stark and her and Arya are similar, wild wolf Stark ladies.
Daenerys Targaryen: Purple roses are for enchantment and enthrallment. Dany's the last(?) Targaryen and her beauty is proclaimed far and wide. Also, it matches her eyes.
Brienne of Tarth: White roses are for innocence, purity, and honor. Brienne's wonderfully honorable, albeit naive. A true knight she is! (Also a virgin, as everyone likes to point out.)
Melisandre: Red roses are for love and passion. Mel sure loves that Lord of Light, huh? Also she's a seductress.
Arianne Martell: Orange roses are for desire and enthusiasm. Arianne's really passionate about stuff. Mostly her line of succession and her old beau Oakheart.
And for ~Hanusen
, as promised: Loras Tyrell