Visually comfortable — what about screen reader users? Effective for people with disabilities? Probably not. Effective for lawyers who make tons of money from suing folks for ADA violations? Possibly. I really wish designers would stop talking about color choices without dealing with the color blindness issues that affect 4.25 % of the global population. And addressing navigation without discussing people who are keyboard only users does everyone a disservice. I assume by the British spelling of “colours” you are not in the US. However, it is a global world.