I could be misunderstanding what you are stating, but it sounds like you are saying that when you were mistaken for white, and diversity practices did not exist, everything was good. But now that diversity practices exist, you need to preemptively point out that you are not white. Now that the conscious or subconscious race pre-determinant is shifting from "this person is white, ergo good" to "this is a person of color, ergo good", you are finding you benefit from clarifying that you fit the latter category, even if it appears as though you fit the former. This may be a "best of both worlds" situation for you.

In any case, diversity hiring may mean that you will be excluded because you are mistaken for white - but that doesn't mean whomever you were excluded for wasn't more qualified than you.