This Photoshop effect makes cool colors (ex. blue) darker and warm colors (ex. red) warmer. The results are glowing skin tones, dark grass and tress, and vivid colors.
The first step towards this Photoshop effect is to identify the cool and warm colors.
Open a photo you would like to edit. Or, you may use the photo used in this tutorial (from iStockPhoto).
The Lab color mode contains a chroma A channel that identifies the cool and warm colors. To access this channel, change the color mode to Lab color (Image> Mode> Lab Color)

Now that we're editing in Lab color, we can grab the channel. But before we do this, we need to create a new layer (Layer> New> Layer or Shift+Ctrl+N) .

After creating a new layer, we'll add the chroma A channel to the layer. With the new layer selected, use the Apply Image tool (Image> Apply Image) to set the following properties:
Layer: Merged
Channel: a
Invert: Unchecked
Blending: Normal
Opacity: 100%
