The plugin is open-source, meaning even though I own the copyright to the code and you can't claim it as your own, you're free to edit it as you please.
In the code, comment out/delete these lines in the cmdLockBlock function. In fact, I would just comment out/delete anything with set_pev(...) in there, and that remove the coloring.
Code:
set_pev(ent,pev_rendermode,kRenderTransColor)
set_pev(ent,pev_rendercolor,Float:{LOCKED_COLOR})
set_pev(ent,pev_renderamt,Float:{LOCKED_RENDERAMT})
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