Tradeoff: Easy on the Eye or Easy to Use

Traveling with work I spend plenty of time in hotels. I noticed that the more expensive the hotel, the more expensive the bathroom fittings. However the more elegant and eye-pleasing the taps and faucets, the harder it is to see which is the hot tap and which is the cold. Some designers focus on form and not function. That sometimes hides the information the user needs. Large red and blue plastic moldings take away from the ascetics of the design, but they do tell the person which tap is hot and which is cold.
The same principle applies to many embedded systems - there is a trade-off between pretty and easy-to-understand. That is why kids toys have big buttons in primary colors. Easy to see and manipulate but not so pretty to look at. Think about that the next time the mechanical designer on the team is trying to make the buttons small an discrete to avoid interfering with the smooth outline of your next product.