I know this is not the best solution but if you want you can use it because right now kibana 4 is not providing any feature(As per my knowledge) so that we can change color of charts from any configuration.

In kibana at the path src/public/index.js following line of code is there. if you change this you can change you colors.

return function SeedColorUtilService() {
    return [
      '#5e87b0',
      '#57c17b',
      '#006e8a',
      '#663db8',
      '#bc52bc',
      '#9e3533',
      '#daa05d'
    ];
  };