Painted Lines on Grass Texture

Wondering how one might achieve the effect of painted lines over a grass texture, as in FIFA or Madden. You can see a similar effect being achieved in Rocket Leage here: Off To A Good Start GIF | Gfycat

My guess is they have a shader that reads color from a texture and colors the grass. The texture they create would be a “layout” of the field. That texture would have an alpha as well so that the grass not affected by the texture will be the “normal grass”. Darker shades of grass would have an alpha with a 50% or less grey and a black texture.

This same technique can be achieved using the dx11 grass asset.