Blend Modes

You can also use layer blend modes to change the appearance of colors in an image. Blend modes allow you to apply different types of transparency effects that determine how a layer interacts with the underlying colors contained in the layers underneath. To apply this method of pseudo recolorization, first make a selection by using any of the selection tools (with the exception of the Magic Eraser, Background Eraser, and Extract filter), or use Select --> Color Range. After your selection is complete, click the New  Adjustment Layer icon at the bottom of the Layers palette and choose Solid Color from the pop-up menu. Solid-color adjustment layers allow you to overlay a chosen color over the underlying layers in an image. You can use blend modes to change the way the overlying color interacts with the colors present in the layers underneath. Choose a replacement color from the Color Picker dialog box that appears and click OK.

Now change the blend mode of the Solid Color adjustment layer to Hue. This is where you may get unexpected results. Depending on the color you’ve chosen to replace and the color you’ve selected with the Color Picker, the new color may appear too dark or too light. When this happens, select the Background layer (or the image layer directly underneath the Solid Color adjustment layer) in the Layers palette. Then F/Ctrl+click the Solid Color adjustment layer mask icon to reselect the color area. Proceed to add a Hue/Saturation adjustment layer. Loading the selection first applies the same mask to the Hue/Saturation adjustment. With the Preview option enabled, move the sliders around until you get the results you want.

Color Overlay Layer Style
A similar blend mode recolorization technique can also be applied by using the Color Overlay layer style. To use this method, make your selection and press F/Ctrl+J to duplicate the image and place it on a new layer above the Background. Click the Add A Layer Style icon at the bottom of the Layers palette and choose Color Overlay from the pop-up menu. Click the color swatch in the dialog box to access the Color Picker, and choose a replacement color. Experiment with the different blend modes until you find one that makes the replacement color appear the most natural when applied to your image. In this example, Linear Dodge worked best when set to 50% opacity. Click OK to apply the layer style.