I wouldn't worry too much about the color scheme. Black and gray is professional, and I think there is a lot more to focus on here. First of all, who is your target market? If it is someone like me who understands an average amount about stocks, you need to do a much better job of explaining your site. The About Us section is just not cutting it. I'm also not sure about the Facebook and Google ads, it may be detracting from your image of authority.