It's not just a badge. Build diversity on moral grounds, rather than simply to show off how you're 'down with CSR'. Get all your people to buy into it.
Think of the benefits. Diverse teams will connect better with customers, who are likely to be equally heterogeneous. They have also been proved to be more creative, better at problem-solving and better at handling conflict.
Be aware. You may be discriminating without knowing it. Offering boozy lunches as a reward may result in some people feeling excluded - a situation that has reached court in the past.
Cover all bases. You've got people of all colours on board - is it then OK to let them send a birthday card around calling someone an 'old git'? You may believe political correctness has run riot, but that doesn't mean you won't find yourself in hot water.
Measure it. Know who applied for jobs, who joined, who left and who's moving up. The figures will help you take diversity more seriously.
Spread the news. If you can show that you provide training around the subject of discrimination and have dealt appropriately with it when it has arisen, you'll be covered when a team member steps out of line.