Light-Haired Swimmer

In anime that aim for a more "natural" look (black and brown hair only), the characters with the lighter hair will either be rebels, fashionistas, foreigners, or spend a lot of time in the water (surfer or swimmer). This trope is about the latter. Some works play it subtle, darker than average skin with lighter than normal hair, while cartoonier works might go for the more visually striking Dark-Skinned Blond. There is some crossover with ganguros, who are sometimes thought of as "beach bunnies", but the light haired swimmer is generally more interested in sports than hitting on people at the pool.

Also note that if the show is inhabited by characters with a rainbow of different hair colors, it's not an aversion if a non-swimmer has lighter colored hair than a swimmer, especially since light hair has plenty of other connotations as well.

A variation of this in Caucasians would be slightly green-tinted hair in blondes.

Truth in Television. Salt water/chlorine and excessive exposure to sunlight can cause black hair to get sun-bleached to brown, as well as making it dry and brittle. This is partly why the dark haired part of Raven Hair, Ivory Skin was once so valued in Asia: It's associated with the rich whose hair were mostly untouched by harsh sunlight, as opposed to the peasants with brown hair. Of course, getting blonde hair from simply swimming is stretching it.

Anime and Manga

 * Maki of Slam Dunk has light brown hair and dark skin from surfing.
 * In the one-shot Piercing, it's revealed Ryota spent his childhood near the ocean, is it any wonder why he has brown hair and tan skin?
 * The main character of Peach Girl is mistaken for a kogal when she's really this.
 * Mizumachi of Eyeshield 21 has the extreme blonde hair-tan skin varient, which provides a nice visual contrast to the raven hair ivory skinned Kakei.
 * Kagura of Azumanga Daioh, though curiously not as brown as Yomi's.
 * Averted in Umisho, which is about a high school swimming club and has a large variety of hair colors, both light and dark.
 * The World God Only Knows: One of Keima's conquests had hair that turned light brown and unmanageable after being on the swim team for so long.
 * Averted in Rumbling Hearts, where the Olympic-level swimmer Mitsuki has dark blue hair. Then played straight after Mitsuki ends up quitting due to a certain accident she accidentally caused. Her successor, Akane, has light orange hair.
 * Discussed in Lucky Star, which doesn't make much sense when only one character in the entire cast even has black hair.
 * In Pokémon, Misty has red hair. The other main characters who do not swim have brown or black hair.
 * In Code Geass, averted as the swim club includes many hair colors. However, Shirley is the lighter - haired of the main characters with red hair, and the coach is a Dark-Skinned Blond.
 * In Rosario + Vampire, Tamao Ichinose (who is actually a mermaid) is the president of the swim club; in the manga she has dark hair, but in the anime her hair is light green. This (dark hair in manga, lighter hair in anime) seems to hold true for most of the mermaids in the series.

Film

 * Bethany Hamilton in Soul Surfer is a blond surfing girl