Take the shine off something
Definition 1 of 1
Pro Tip 1/3Lessened Joy
Refers to a decrease in happiness or enjoyment due to a specific negative event or detail. 
Winning the award would have been perfect if it weren't for the rude comments that took the shine off.
Pro Tip 2/3Subtle Disappointment
Expresses a sense of subtle disappointment that does not completely ruin the experience. 
The unexpected rain couldn't take the shine off our beach day, we still had fun.
Pro Tip 3/3Idiomatic Usage
Used figuratively and not meant to suggest anything about physical 'shine' or brightness. 
Finding a typo in my thesis really took the shine off my submission day.