Yes -- I'd go with some (but not too much) bold or demi-bold light text on a dark background -- for, as Frances said, to catch attention. And, as you mention, to reduce power consumption. Seriously! Last September, the lights went out bigtime here in San Diego one evening. We drove up the coast, town after town, and finally found a bar in San Clemente that had a generator, about 500 thirsty Marines, and my wife and I. This shocking situation, 'retired couple drives 50 miles to get a drink', would NEVER have happened had our area's graphic artists used white or lime-green bold sans-serif fonts on power-saving black backgrounds...