Justin thinks later that what he loved about Britney was her brightness.
When they were both little kids, whispering to each other between skits at Disney, they were the same, hair like honey and bright teeth and shining, glaring talent. Britney still has that now, and so does Justin.
That is not what he loved.
Justin loved that, when they were both "grown up", he could look at her face and see nothing genuine. Hair so flatly yellow, face a cool smooth peach, lips pale shell pink. Britney always looked like she'd been shaded in by colored pencils, fake pigment on white paper. Britney was bright and false like neon.
The best part was that she truly was what she appeared to be, with no mixed messages and nothing to analyze. There was nothing confusing about her. Britney was as brightly pastel on the inside as she was on the outside.
Justin thinks later that he loved her because there was nothing dark about her; even her brown eyes were more mahogany and her roots were never visible long enough to interrupt all that smooth false blondeness. Her smile was a bright and true and blinding as the sun.
Justin thinks that he probably mostly loved her because she wasn't like Chris. Not at all.