Painter 2018: Colors appear fade when opening 2018 RIF files with thick paint, liquid ink or impasto in Painter 2017

Colors appear fade when opening 2018 RIF files with thick paint, liquid ink or impasto in Painter 2017

Workaround:

If the user still has access to 2018:
Open the document in 2018
Set the Ambient Lighting - Brightness to 0%
Set the Directional Lighting - Brightness to 1.20 (approximately default lighting value) or as desired if the user had been using non-default lighting
Save the document, and it should now open in 2017 as expected

If the user does not have access to 2018:
Select the canvas in the 2018 document
Select all (ctrl/cmd+A)
Edit copy
Edit paste to new image
Now copy each layer over individually