The color scheme of the website is an indispensable part of ensuring a healthy and effective user experience. It is the color scheme of the website which determines its success or failure. You may have the best content possible on your website, may provide the most lucrative product deals and etc, but if the color scheme is not inviting and engrossing enough, you may better bid adieus to your aspirations for online business success.
I would argue that layout is equally important, but color choice is vital.