Many people say that breakfast is the most important meal of the day, so it's also important that you look your best! While there are not dedicated, 'breakfast clothes', business casual clothes can be appropriate for breakfasts outside the home at a nice restaurant or for an early business meeting. Remember, breakfast is the first time in the day you might make an impressions on someone, so you'll want to look your best.
Especially for a leisurely breakfast, less formal attire is recommended. sport coats are almost never recommended and dark pants should be avoided. Lighter colored chinos with a light colored button down shirt are the most appropriate. Matching brown shoes, socks and a belt should also be worn. Breakfast is typically a laid-back affair, so dressing to formally will make you look out of place.
As with any meal, remember to be careful of spilling food on your clean clothes
Typically less formal clothing is appropriate
Lighter colors are recommended for the morning