Why are their colors orange and red? That looks a bit off. If the orange means "default", then I think that should be represented in a standard way. Doesn't a box with a broken outline usually signify "selected" as far as pressing Enter is concerned?
Are you referring to the "Are you sure?" popup box? Forb made three types of buttons and I have been using them as follows:
Orange buttons are action buttons. Clicking on them will often progress you further through the UI and possibly do something which takes a bit of time/effort to reverse (eg loading a game or switching to a new room). In popup boxes their hotkey is enter.
Teal buttons are option buttons. They usually do easily reversible things and/or optional configuration. Sometimes they push the user into submenues which are easy to pop out of.
Red buttons are negative buttons. They cancel behaviours or leave rooms, popping the user closer to the root of the UI. In popup boxes their hotkey is escape.
Why are their colors orange and red? That looks a bit off. If the orange means "default", then I think that should be represented in a standard way. Doesn't a box with a broken outline usually signify "selected" as far as pressing Enter is concerned?