jaundicing

Jaundicing is the present participle of jaundice, used as a verb meaning to affect with jaundice or, more commonly, to distort someone's judgment or perception with negativity, envy, or bitterness.

The metaphor draws from the yellow discoloration that jaundice causes—as if one's view of the world has been tinted by illness.

Years of disappointment had a jaundicing effect on his outlook.

A jaundicing influence makes someone cynical or prejudiced where they might otherwise have been fair-minded.