The following description was taken from Marilyn Roxie's About the flag page:
The genderqueer pride flag is a Marilyn Roxie design, 3rd and final version created in June 2011, modified from version 1.0 in June 2010, and 2.0 in September 2010. The design is aesthetically similar to the gay and lesbian, bisexual, transgender, asexual, and pansexual flags; that is, horizontal bars of color with special meaning. The meaning of the colors in the genderqueer flag design are as follows:
Lavender (#b57edc): The mixture of blue and pink (traditional colors associated with men and women, present on the transgender pride flag) as lavender is meant to represent androgynes and androgyny. Also represents the “queer” in genderqueer, as lavender is a color that has long been associated with “queerness” , including gay, lesbian, and bisexual communities.
The three colors are not meant to indicate that any of these identities are entirely separate or opposites of one another conceptually; they are all interrelated as well as key concepts in their own right, and there are more concepts and variation of gender and sexuality present that tie into genderqueer identities than can be listed here. The purpose of the flag is to help create visibility for the genderqueer community and related identities.
Use by Nonbinary.org
As genderqueer is an umbrella term with similar scope to nonbinary, Nonbinary.org has adopted the genderqueer flag as part of its logo. Each of the identities and experiences described as represented by each colour in the genderqueer flag are covered by the nonbinary umbrella. As such, there is a strong argument that the flag also serves very well as the nonbinary flag.