Whether you manage a global brand or just run a dinky little blog like this one, you've probably at one time or another thought to yourself, "it's time to redesign the logo/website/theme/brand." Here are some reasons why you were probably wrong.
Familiarity breeds contempt.
As much as I'd like to think people look at this site as often as I do and pay as much attention to it as I do, odds are that I am the number one reader by a wide margin. Similarly, hardly anybody lives your brand or views or your design work as much as you, its owner or custodian, do. Just because you got bored with it does not mean that anybody else has. (Remember when you opened your overflowing closet and declared, "I have nothing to wear!") Do your homework and your research before embarking on a redesign.
There's a real risk that you'll just duck it up.
You know that flowchart that starts with "does it work?" then goes through "did you fuck with it?" and ends with "you poor bastard"? Think New Coke. Think Gap logo. Think hard about whether you can really make it better.
Consistency is the hobgoblin of successful branding.
Change is good. Don't get me wrong. I change my clothes every day. Of course, I also wear the same colors every day. Your brand and design are like that. If you change too much or too often, nobody will recognize you. Carefully weigh the cost of change against the miracle of compound interest on your identity.
Expense is not just money, it's also time and focus.
A redesign is seldom a cheap project. Big brand work costs megahubys, and even redoing a humble header graphic yourself can be a terrible time sink. Ask yourself, are you sure this redesign is the best use of available money and time? Your graphic identity is a manifestation of your brand; your brand is a manifestation of your product, your customer service, your content. I'm betting that you'll do more for your brand by improving your offering (if you're a blogger, that's your writing, folks) and how you deliver it than by refreshing your colors.
Polish pixels or push product? The choice is yours.