Apply step gradient color in echart [gauge-ring]

Question

gauge-ring

What should I write in the color attribute? to make the color similar to the image below

progress: {
  itemStyle: {
    color: ????
  }
},

I tried the following code before, but it seems to have no effect

progress: {
  itemStyle: {
    color: [
      [0.25, '#FF6E76'],
      [0.5, '#FDDD60'],
      [0.75, '#58D9F9'],
      [1, '#7CFFB2']
    ]
  }
},