Picture of a bi-color gradient nail design

Quick answer：

Bi-color gradient nail designs are a popular nail art trend where two different colors are blended together in a gradient pattern. This design typically involves a base color and a secondary color that gradually blend into each other, creating a visually appealing and stylish look. The process usually requires careful application of the colors to achieve a smooth transition between them. Popular choices for these designs include contrasting colors like black and white, or pastel shades.