* It could be a statement about race or ethnicity: This is the most likely interpretation, as "white" and "brown" are often used to refer to racial categories. The statement could be a simple observation of different skin colors, or it could be more nuanced, expressing a sense of difference or even conflict.
* It could be a reference to a specific situation or object: For example, someone might say "You on white, I am brown" while playing a board game or looking at a picture with different colored elements.
* It could be a nonsensical phrase with no intended meaning: People sometimes use incomplete or nonsensical phrases for various reasons, such as humor, irony, or simply to express confusion.
To understand the meaning of this phrase, you need more information about the context in which it was used.
If you provide more context, I can help you better understand what it means.