Immature Ring-billed Gull

My Sibley Guide To Birds says this is a "first winter," juvenile ring-billed gull. I had someone ask about the difference. The adult has a notable grey coloring to the top of their wings and the undersides are pretty pale. The juvie's have a lot more brown in their upper and underside wings in their first two years. Feel free to correct or add information if you have it.