Your brand is not your logo or color scheme, it's how people think about you. It's the way that you represent yourself.
Your brand is how people perceive you. The visual component is just one part of it. Are you fresh, reliable, exciting, reactive, aggressive, friendly, simple, powerful, flexible?
You can't be everything at the same time, so pick a set of values that you can really stand by, and make sure those come across consistently.
How to pick the right values? There are not really any right choices (though of course, there are negative values that you should probably avoid), so make sure you pick core brand values that you believe in, and which aren't exactly the same as everyone else in your industry (otherwise, how will you differentiate yourself?).
It's a worthwhile exercise to put together a "branding document", informal or formal.
