Use PS to create rainbow color non-mainstream effects

Original picture

final renderings

1. Open the original image and first create a hue/saturation adjustment layer. The effect is as shown in Figure 2.

<Figure 1>

<Figure 2> 2. Then create a new layer, set the layer mode to Screen, and then use a 48px hard brush to paint the following color.

<Figure 3>
3. Execute Gaussian blur filter. Get the final effect.
<Figure 4>
<Figure 5>