Til they blacking out their tears like it's lights out
Bring em out the black like a lighthouse
Lu is referring to the teardrop tattoo here, which has many meanings, but they all come back to violence, in one way or another.
Knowing that, Lupe uses the contradicting connotations of “tears” (violence/sadness) to illustrate that the youth are probably trying to hide or express their sadness through acting out in violence.
The successive line is referring to how Lupe is going to act as a lighthouse (the beamin' light, if you will) for those kids who think they are trapped in their “tattoo-tears world”; if they are lost at sea (metaphorically speaking), he is going to save them through his positive lyrics.
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