Old wrecker

[gwpriester]

If you make a bitmap version of the image with the bright colors you can reduce the Saturation in Photo Tool > Enhance.

Or, place a rectangle over the entire image, apply a 60-90% black fill and apply a Flat, Saturation transparency. Black will create no saturation, grayscale, and white creates total saturation. So you can vary the fill color until you are happy with the saturation.

In the attached example, I placed a rectangle with Black to 50% Black Linear fill and applied a Flat Saturation transparency so you can see the degrees of saturation.