d3 颜色转换 十六进制转RGB

d3 color
https://github.com/xswei/d3-scale-chromatic

var color = d3.rgb("#fff")
/*
Rgb {r: 255, g: 255, b: 255, opacity: 1}
b: 255
g: 255
opacity: 1
r: 255
*/
color.toString(); // rgb(255, 255, 255)