Hey there is a quick tool for that, I found it in Clip Studio Paint, Corel Painter, Krita & I believe I see the Icon in photoshop (I just can't test it). Look for an Icon with a checker pattern, it also has a lock with it some times, this locks the transparency on that layer so you can’t draw on any of it. It’s great if you want to change the color of your line art.
Just look for an icon that kind of looks like this.
