 A warm white LED is best used with a yellow or orange face.Since the advent of LED lighting technology, channel letters have become thinner in depth, decreasing to as shallow as from , a trend which began in Europe, and is seen increasingly in the United States.These are standard channel letters, but the neon is covered with a clear acrylic face to keep birds from making a nest as well as to protect the exposed neon from outside elements, i.e., weather, etc.