The original picture ( hue slider at 0 )

The hue slider set to +90

The hue slider set to +180 or -180

The hue slider set to -90

Corel Photo-Paint: Image/Adjust/Hue/Saturation/Lightness

Adobe Photoshop: Image/Adjust/Hue/Saturation...

A standard feature in all graphics software, the Hue/Saturation filter universally changes the colours of an image. The Hue slider shifts the colours through the whole spectrum. With the slider at +180 or -180 the shift will be the direct opposite end of the spectrum i.e. red to green, blue to yellow. The Saturation slider adds or subtracts colour depth.

Above, the Photoshop Hue/Saturation dialogue box and below the Photo-Paint.