How do I flag emails with different colored flags on iPhone?

Flagging emails is a great way to separate important emails from the clutter and make them easier to find. iOS 13 finally gives you color options for your flags, so now you can distinguish between your flagged emails. For example you might use red for high priority, urgent emails and purple for all emails regarding a specific subject, green for all emails from a specific person, etc. To do so, open the email you want to flag and tap on the reply button to pull up the new and improved reply menu. Tap on Flag and you will see different color options. Just tap on one to add a flag of that color.