Yeah, it looks like the dark grey layer underneath the tan showing through. They probably just did one or two quick coats of the tan colour and didn't worry about coverage being perfect on the sides. It's more pronounced there, but you can see the same thing happening on all of the sides of those earpieces.
It's definitely a detail not everyone replicates on their helmets. As amazing as Rafalfett's stencils are, they aren't going to capture every imperfection and detail on the helmet, like oversprays, uneven coats, misting, washes. etc. Its good that you're studying the photos, because that's how you notice details like this!
