The concept was a screen that contained no backlight, but used special elements with reflective surfaces that reflected certain colors of light. These surfaces could be switched between two states, reflecting and absorbing, when absorbing the unit would appear black. Qualcomm did eventually launch a Smart Watch using Marisol, but it never went anywhere. Although the panel was easily viewable in bright light the colors were not vivid and the display tended to appear washed out. Eventually Qualcomm to a bit hit and closed the division down.
Now Apple has bought the lab where Marisol was developed and produced. They have also hired some display technology people from Qualcomm and AU Optronics. This could mean the Apple is taking up the Marisol project or it could simply mean they are working on another display technology on their own. We know that Apple has been trying move away from the big partners like Samsung, LG and Sharp for a number of years. They tend to like to deal with smaller companies so they can exert more control when it comes to supplying product. Samsung, LG and even Sharp can push back against Apple and demand more favorable terms.
If Apple is resurrecting Marisol they have their work cut out for them. Reflective technology based displays can be tricky when it comes to color saturation. Apple might be able to spin a lot of things to their fan base, but we are willing to be that a dull washed out display is not one of them.