I will defer to the I’m a Grandma and a Iowa State Cyclones fan which means I’m pretty much perfect shirt so you should to go to store and get this physicists on this one, but this is my take. It isn’t the atoms that make your shirt colorful. It’s the bonds between atoms in the dyes that are attached to the fibers of your shirt. A photon that encounters a bond between two atoms causes the electrons in that bond to go elsewhere, absorbing the photon’s energy. The lack of that (bluish) photon causes humans to perceive a (red) color. That’s how you get a redshirt. Then don’t tuck your shirts in! You probably could get away with it in a more formal setting if you wear a lightweight v neck sweater over it.