

There is a difference between colors you see from reflections, and from a direct source.
Your t-shirts is light hitting them, and reflecting back to your eye. Depending on what is reflected and what is absorbed, you will get a colour.
But that will not be the case from screens that emit their own light.





It’s not running an individual desktop for each screen. The screens are just mirrored to one desktop.
You’ll usually have a couple of “ad desktops” and then you just hook up multiple screens all over your facility to those desktops, so you have some redundancy and can easily run different ad cycles so they all don’t sync up.