AT&T Brand Guidelines at a Glance 13 Vibrant Color Vibrant colors are derived from the AT&T primary and secondary color palettes to create a highlight gradient that radiates off the page. Please download Working with Vibrant Color: A Step-by-Step Guide (PDF) for more information on constructing a vibrant color. The arc templates are available for download on the AT&T Brand Center. AT&T color palettes for use on arcs and backgrounds are embedded into each arc template file.