NEW YORK — It's as red as Santa's suit, a poinsettia or your neighbor's ugly Christmas sweater. Yet Starbucks' stark new holiday coffee cup has set off complaints that the chain is making war on Christmas. The outcry — which gained in intensity after Donald Trump suggested boycotting the coffee chain — illustrates the fine line companies must walk during the all-important holiday season: They want to stand out from their competitors, but not go so far as to offend or unsettle.