Some years ago I used a cheap laptop which was quite okay for my use cases back then. From time to time I recognized, that the things that I thought are pretty balanced actually look awful on a high contrast display (the MacBook at work).
Especially while editing photos, the low contrast combined with the low processing power, made me realize, this laptop is no good for my use cases anymore. Nowadays I use a Mac with a Retina display and the contrast is awesome. When editing photos or designing something, I still make sure to check it on a low contrast device, as I am aware that not everybody has a high contrast display.
I surfed the web the way I think a lot of people do, on a monitor that they took out the box and started using without doing any calibration. I was astounded by the lack of contrast all over the place. We like gray a lot and often we like it to be very subtle.
-- Susan Robertson in A List Apart
So, use something like Contrast Ratio by Lea Verou to check the chosen colors and contrast. The best verification is to get a low spec, low contrast monitor that actual people are most probably using. It’ll help a lot.