Longtime lurker coming out to defend contrasting collars. For whatever reason, I am not a fan of collars with stripes or most other patterns, so I have white collars and cuffs put on my otherwise patterned shirts for business. Also, I think white is a very good color for my skin tone, and so having a contrasting collar (and of course cuffs) allows for better framing of the face and the infusion of color and patterns. Since most of my shirts are solids, contrasting collar shirts are by no means a linchpin of my wardrobe, and I probably would never try to make this a common look. I agree that this look is out of place in casual wear.