Illustrate a captivating silver holographic universe in the form of a round spiral, where shimmering colors and iridescent hues cascade in mesmerizing patterns. Utilize digital painting techniques to create the spiral shape, with holographic stars and galaxies swirling along its curvature. The holographic effect should give the illusion of depth and movement, with colors shifting and changing as the viewer's perspective moves along the spiral. Incorporate subtle variations in color and texture to enhance the holographic effect, with hues ranging from silver to iridescent purples, blues, and greens. Pay special attention to the lighting, using soft, diffused light to highlight the holographic elements and create a sense of atmosphere. Experiment with composition to draw the viewer into the enchanting beauty of the silver holographic spiral universe, evoking a sense of wonder and awe.