var data1 = [];
var data2 = [];
const alpha = 0.8;
const bg = 255;
const clr = 90;
const n = 10;
let currentClr = bg;
for (let i = 0; i < n; i++) {
data1.push([i, currentClr]);
currentClr = currentClr * (1 - alpha) + clr * alpha
}
for (let i = 0; i < n; i++) {
a = Math.pow(alpha, 1 / i / i / i);
data2.push([i, bg * (1 - a) + clr * a])
}
option = {
xAxis: {
type: 'value'
},
yAxis: {
type: 'value'
},
series: [{
type: 'line',
data: data1
}, {
type: 'line',
data: data2
}]
};