If you want to use a microwave ovens your task is pretty simple: you want to heat something. The variables involved in accomplishing your goal are:
That's it. Then why is nearly every microwave I've ever used so complicated? For example, I give you the microwave at my closest work kitchenette:
The primary problems come from button placement. Why are 'Custom' functions at the top? For most tasks you just need the 'start and add 30 seconds for every press' button. And, to its credit, this microwave does have it. Can you find it at a glance? Me neither. (It's next to the 'Stop' button.) Problems with it:
Another notable violation the 'Start' button. Except for the tough-to-find 30 second button every single use of this microwave will involve that button. So why is it:
The coloring thing is what gets me angry almost as much as the placement. I could almost understand if none of the buttons had coloring. But that's not true, the 'Stop' button has a red circle. So why not make every button that makes the microwave run green? Or the 'handy' shortcut buttons up top purple so your eye will group them together separate from the rest. (And why are they on top anyway?)
A couple other minor issues:
(You'd could argue that this isn't a microwave design problem. But what if they reduced the 'Popcorn' cycle by 30 or 45 seconds? Think of all the noses saved!)