1. Create a new image in Photoshop , such as 400×200, and make sure the color is the default black at the front and white at the back. Create a new layer.
2. Use [Filter_Rendering_Clouds], and the image will look roughly as shown below.
3. Use [Filter_Distortion_Glass] and set it as shown below.
The finished effect is as shown below.
4. Use [Image_Adjustment_Color Balance] to set the midtones as shown below.
Make similar settings for the highlights. The effect is as shown below.
5. Then [CTRL_T] use Free Transform on the layer, then select perspective to make a trapezoidal perspective. The final effect is as shown below.
Summary: Use color balance to colorize grayscale images. Through different settings of shadows, midtones, and highlights, you can create rich effects.