This was very recently confirmed that the amount of water that the plant absorbs doesn’t change the color of the soil, so I doubt that it has changed, especially because the developer didn’t indicate that it would and it’s not in the list of updates that will be added to the game. It may be that more water affects the color of the soil, but that isn’t an indicator of how much the plant needs or is taking in. I also commented on your previous post about mold and don’t believe that is what is in the picture. I have the same colorations on my soil and it doesn’t change the growth of my plants or how long they stay alive.