Yang Xiao Long

Yellow is one of the main characters in RWBY. She is due to make an appearance on June 1st at A-Kon in Dallas

Speculation
 Note: The following is fan speculation, and is not to be considered canonical.

It is suspected that Yellow's fairy tale allusion will be "Sleeping Beauty", with both the lines in "Red like Roses" that relates to her (Yellow beauty burns gold), and the title including the word beauty.

Fans have speculated that Yellow's weapons are pistols based on the interpretation of her title card silhouette, but no information currently exists either supporting or disproving this. The lyrics of Red Like Roses hint at a possible connection to Yellow and fire, light or the sun (Yellow beauty burns gold), although whether it is an ability, weapon or simply a vividly descriptive allusion is also up to speculation.

Yang (阳), the Chinese character for sun and/or light, is believed to be a possible name for Yellow. This theory is supported by a photo tweeted by Monty Oum showing a open folder named "Yang", while working on Yellow. But it could also just be the name of one of the 'rival teams', the bearer of the crescent moons.

Analysis of her silhouette reveals some information about her clothing, as shown below. It appears as though Yellow's clothing is armored. The sharp edges to her dress in the initial silhouette suggest a plated kilt or dress and the larger shoulders suggest shoulder guards, perhaps a pixane or pauldrons. This might suggest a "Joan of Arc" stylized clothing, and perhaps persona. The knight style armor, however, is a stark disparity to the speculation of pistols or small firearms as her weapons.

Further analysis into the poster advertisement posted by Barbara for the upcoming trailer, we see further evidence of the plated edges along Yellow's midriff as well as what appears to be a pair of vambrace on her arms.