You can create interesting hybrid colorized black-and-white photos by allowing the colors in the original image to partially show through from lower layers.
The source image (Figure 10-48) has nice bright colors, but its monochrome cousin is a good photo too (Figure 10-49), even if it is a little dull. It results from a simple conversion using Photoshop’s Black & White command, as described in Black-and-White Conversion Using the Black & White Command. Figure 10-47 shows the resulting Layers panel. Before converting it, we tuned the image using Shadows/Highlights and sharpened it using Smart Sharpen.
Figure 10-47. Our Layers stack ...