How do you presume to know just how colleges use such information (race/ethnicity/income)? Why do you think your situation, the challenges you faced, won’t be recognized and evaluated fairly? Colleges do take into account high school context/profile, so if you didn’t have the opportunity for AP courses, or extensive ECs, or other things, they’ll be aware of this. They likely even consider other aspects of the city/community you grew up in.
If you like, feel free to write about the challenges you faced and how you handled them, got past them, or at least mention them, in your essay/written supplements. Just be careful not to do it in a way that’s seen as privileged or whiny.
Your putting “disadvantaged” in quotes bothers me – it shows a lack of appreciation for the difficulties that can lead to. I’m sure it’s true that colleges sometimes do use such factors in a superficial/inaccurate/unfair way, and maybe there are relatively simple ways to improve how they do that; but all things considered (the space they have to collect such info, the time they have to assess it, the way their results are evaluated, etc.), I don’t think it’s unreasonable or unfair that they do use it.