What about the category of "Brown"?

While reading Hartigan and other assigned texts that focus on whiteness and blackness as relational identities, especially in relation to one another, I have thought about what might be in between. Especially after I made a sarcastic generalization about "white people" the other day to one of my friends who asked me what the hell I considered myself to be? And well, if it is all relational, then I am left with only blackness and whiteness to choose from and it is a frustrating concept for someone who, like me, does not necessarily identify with either extreme (even if they are sliding scales). This led to him asking if I considered myself "brown." And, yes, like most mestizos I definitely consider myself part of the "brown" contingent. Yet this term is problematic in the United States because of the many immigrants and race mixing (although not on par with a place like Brazil), so maybe that is why the majority of Hartigan's focus falls on white and black. Also, while an extremely fast growing minority, Hispanics have only more recently become a sizeable player on the national level. So, on the scale of blackness and whiteness I believe that we need to talk about the gray (read: brown) area. There is an interest book that is written by Richard Rodriguez entitled Brown, which is about his experience as neither black nor white growing up in the United States. I hated the book when I read it as a freshman, but now as I look back it was quite a good commentary on the space that exists between black and white. I am one of the "gappers" in this sense. However, even Brown has a sliding scale... I came up with the degree of "brown" for myself as caramelized. There are plenty of other degrees on this scale. While it may also be relational, it has to contend with both of the other relational identities to even achieve legitimacy. Please let me know your thoughts about the concept of "brown" and/or "brownness."