Rather than coming with some kind of travel holder to connect it to the tablet, the "Pro Pen" comes in its own travel box with a selection nibs and color-coding rings.
In two of the trials, the box was dark for 12 minutes and then illuminated for 48 minutes with either long-wavelength red light or short-wavelength blue light directed at the subjects' corneas. (Light color is determined by its wavelength.) The box was dark in a control experiment.
Huge swatches of neon yellows, reds and lime-green swiped across every surface try to provide the color-coding necessary to find one's way around within the vast black box.
In the Colors dialog box, click the Custom tab, then click in the Colors display to choose a basic color, and use the shading slider to the right to pick the exact shade you want.