Testing the watercolor pencils with my paint for the mural. You can see the regular pencil through it (see purple wash). The watercolor pencil dissolves into the paint, causing a line when it’s a strong contrast (see red against light pink leaf) but not when it’s an extremely similar color (not pictured because you can’t tell where it is). I did not test a 4B pencil. I think I just need to use pencils very close to the color I am painting, or I could use white since all of my colors are pastels.