Ephasize Color is a color effects iMovie plug-in is a more specialized version of our "emphasis" plug-in. Instead of emphasizing strong colors, you can now choose which color to accent by boosting or reducing it. As with all our intelligent plugs-ins, you can choose to also affect similar colors and control how similar the colors may be.
Use this plug if you want to accent a certain color (or color range) or reduce the prominence of a color in your clip. Use it also to create special posterize effects.