1. Create a new image, 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_Distort_Glass], and set it as shown on the left. The finished effect is as shown on the right.


4. Use [Image_Adjustment_Color Balance] to set the midtones as shown on the left, and make similar settings for the highlights. The effect is as shown on the right.


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.