HSL 3.0 - Popular Updated Pick Clean

HSL is an iMovie plug-in that allows direct color control via the hue-saturation-lightness model (as opposed to the more intuitive red-green-blue color model many people are familiar with). The biggest advantage of this is that it lets you make colors more vivid through directly manipulating color saturation. the plug allows shifting color hue 50% left and right, and adding or subtracting up to 100% saturation and lightness.

What should I use it for?

make colors more vivid or bleach them out (saturation control)
correct color shift (hue control)
make dark clips brighter, and bright clips darker (lightness control)