NO ITS OK i get that i know what you mean. a lot of people ask the same. to be completely fair i don't know how to explain either LOL. i just use brushes that look better with that technique. anyways.
the thing is that i copy the layer with lineart, lock it ( so the only lineart will be affected iykwim ), color it with any color of the choice ( i usually go with red or cyan-ish ) and then apply any effects that work well. like " saturation ", " difference ", "exclusion ", " multiply ", etc. any work, really, it;s the matter of taste and what you want to achieve.
i personally dislike when people try to do the same since i've been using it as long as i can remember but also i do not own this nor invented it so it;s ok just don;t really show it directly to me. something something bpd something something insecurities issues. it doesn't matter. just hoping i explained it somewhat understandable