I can't change the colors of a D3 Donut

I’m stuck on a little problem, I don’t know JS at all. I would like to put half of color on the left, the other half on the right, while there is one that: var colour = d3.scaleOrdinal(d3.schemeCategory20); which bothers me.

How to add a color for each “piece” of the donut? I want this color on the left : #273c4e and this one on the right : #b7ce39

I try this : length = someInteger; colour = d3.scale.linear().domain([1,length]).interpolate(d3.interpolateHcl).range([d3.rgb("#273c4e"), d3.rgb('#b7ce39')]);

Thank you.

Link of the donut : Click

Okay so what they did was

var seedData = [{
  "label": "React", //sets the name of the donut space
  "value": 25, this is how much % of the circle it covers 
  "link": "https://facebook.github.io/react/"//is the link if u click it it will redirect u
Thats about the size of it if u want to change it u need to change the value
as for the colors:

// Define arc colours
var colour = d3.scaleOrdinal(d3.schemeCategory20);

its in a scheme linked to somewhere else
if u like to change the color u have to change thart