Crazy horse leather is made through a process of applying a special purpose wax to a buffed full grain leather. Depending on the amount of wax applied to the leather determines how dark or light the finished color will be.
Because of this, some crazy horse leathers come in various shades of brown, tan, brown, dark brown, and espresso browns. Crazy horse leathers that are of lighter browns have had a very thin layer of wax applied to them. And crazy horse leathers of darker browns have had much more layers of wax applied.
Often times you may find that with crazy horse leather bags, the color shades from one area to the next will vary greatly. There will be areas of the leather bag that are much shades darker, and other areas where the shades are lighter. This is because the wax application isn't always flush across the entire leather cut. Or in some areas, the leather fibers are more absorbing to the wax than in others.