Choosing colors for a website is fun, complicated, and takes some time.
Your industry + your style + your customers: what's going to work? Keep in mind that colors show up differently on all monitors. You can't control how someone else's monitor is set. Also...mobile devices won't show what your desktop or tablet shows. A large monitor shows a great background image or colors, but mobile and tablets won't.
I come across different color tools and like to share so here we go:
SPECIFIC BRAND COLORS?
If you have a specific color but want a variation darker or lighter try this website. You can get a color code from your printer or maybe you already know how to do that. There are color picker tools for different browsers.