Warning: Using a white dash mat will reduce your visibility through the windshield. When sunlight hits the mat, it will cast a white reflection on the inside of your windshield that makes it extremely difficult at times to see through. I know this from experience. Try this... place a white piece of paper on top of your dash on a sunny day and you will see the difference. I just wanted to warn you before changing the color of your dash to a lighter one... because it would suck if you payed money for that and then decided you don't like it later.
Hey, but check out your local interior upholstery shops to see if they do it. I know a place in my area that will make custom dash mats and they will embroider any words or designs you want on it.