GradientTexture

<mesh>
  <planeGeometry />
  <meshBasicMaterial>
    <GradientTexture
      stops={[0, 1]} // As many stops as you want
      colors={['aquamarine', 'hotpink']} // Colors need to match the number of stops
      size={1024} // Size is optional, default = 1024
    />
  </meshBasicMaterial>
</mesh>

import { GradientTexture, GradientType } from './GradientTexture'
;<mesh>
  <planeGeometry />
  <meshBasicMaterial>
    <GradientTexture
      stops={[0, 0.5, 1]} // As many stops as you want
      colors={['aquamarine', 'hotpink', 'yellow']} // Colors need to match the number of stops
      size={1024} // Size (height) is optional, default = 1024
      width={1024} // Width of the canvas producing the texture, default = 16
      type={GradientType.Radial} // The type of the gradient, default = GradientType.Linear
      innerCircleRadius={0} // Optional, the radius of the inner circle of the gradient, default = 0
      outerCircleRadius={'auto'} // Optional, the radius of the outer circle of the gradient, default = auto
    />
  </meshBasicMaterial>
</mesh>