Solid blue gradient nail designs refer to nail art that features a smooth transition of shades within the blue color spectrum. These designs are popular for their simplicity and elegance, often incorporating various shades of blue to create depth and interest. They can be applied using gel polish, acrylics, or even natural nail polish with the help of a nail art brush or a special gradient pen. This type of nail design is suitable for both casual and formal occasions, and can be customized to suit different personal tastes.