This template lets you choose one base color via the documentclass option changecolor. You can for example use the color of the company you are applying for. By using a color harmony model, a color named second is picked. This color is only used for the links. However, if you choose the option titlecolor=second, the second color is also used for the titles. See the gif below for a little demo.
By choosing colors according to a color harmony model, you make sure the different colors match nicely. You can play around with different models here. For more information on how this template works, see the comments in cv-roald-example.tex.