About 14 years ago I designed shirts I called "Mixed Media" because of the different patterned fabrics used to make one shirt. Often placing one patter under the cuffs while another on the rest of the shirt. The placket or an under collar would be other placements and there were many combination possibilities. The Robert Graham brand is perhaps the most known for this look today and seen often on the popular ABC show Modern Family.
Surely anyone is free to dress the way they want to but are there situations where there might be a right and wrong? Should you expect your haberdashers to educate you to as to how to wear the clothes you purchase from them? Yes.
I'm not sure at what age we learn to roll our cuffs, but we learned to roll the cuff once in the amount of the actual cuff and then we do it again. Doing it like this tends to secure the cuff relatively well in keeping it from coming undone. However, when the cuff has a contrasting fabric underneath rolling it in this manner will completely defeat the purpose of using the contrasting fabric.
The majority of the time I see men resolving this issue by rolling the cuff once as you see on the picture on the left, thus exposing the contrast but it doesn't secure the cuff in place very well at all. In the picture on the right you see what I consider the correct way to wear this type of shirt. It is easily achieved by rolling the cuff the first time more than the usual length of one cuff but at least a cuff and a half. The second roll, now is actually done not using the cuff, but part of the sleeve fabric to end up looking as you see above.
On the right you also see that this shirt has contrasting fabric on the inside placket which I prefer in a shirt. The man on the right added insult to injury in my opinion by wearing a white tee shirt underneath. If you feel uncomfortable due to excessive sweating I recommend a v-neck undershirt and making sure the shirt is buttoned enough to cover it.
You only get one opportunity at the right first impression don't miss it.