The central subject refers to actual coniferous trees, typically firs or spruces, that exhibit a bluish or silvery-blue hue in their needles. This coloration arises from a natural waxy coating on the needles, which reflects light in a way that creates the blue appearance. Colorado Blue Spruce is a prime example.
The appeal of these trees stems from their distinctive color, offering an alternative to the traditional green Christmas tree. They can provide a unique aesthetic for holiday decorations. Their hardiness and symmetrical shape also contribute to their desirability, as they tend to hold ornaments well and maintain a pleasing form throughout the holiday season. Historically, while green trees have been the norm, variations in needle color have always been present in nature, with the bluer varieties gaining prominence as ornamental choices.