by Johann Gudbjargarson
A powerful addition to Lightroom is the ability to change saturation, lightness, and hue for different colors. Until now, this feature wasn't in Camera Raw, and the need to go into Photoshop to alter each color channel made the workflow and management of pictures a lot harder -- you'd have to manage a different version of the picture, not to mention the additional steps involved in taking the picture into Photoshop for an otherwise simple adjustment.
One of many uses of this powerful Lightroom tool is to make blue skies bluer, similar to the effect of a polarizing filter. To do this, simply slide down the blue lightness slider in the HSL panel to make the sky more striking. This technique can sometimes transform a rather dull landscape into a very good one. Here is a example of this method:
More extreme usage of this function is to change colors with the hue slider, although that's something I rarely do with blue skies.