Photoview: loss of colour saturation when saving image as png

In the photoview window, the colours look fine, but when exporting to .png, the colour saturation in the transparant parts decreases.

See attached picture:

On the left side, an image saved as .png (opened in Windows photo viewer). On the right side, the image as seen in the photoview window.

Problem does not occur when saving as .jpg, but I want to keep the transparancy.

Image is rendered with the scene "Soft Box" applied, using only Primary photoview 360 lighting. The liquid part's diameter is 0.1 mm smaller than the inside of the glass.

Any ideas, community?

SolidworksPhotoview 360