Q&A for How to Change iMessage Color

Jailbreaking allows you to open the operating system of a phone to manipulation, allowing you to change aspects of the phone that were not originally intended to be edited by people outside of Apple. Because of this, jailbreaking your phone violates the warranty (since it counts as the customer using the phone for purposes it was not intended for).

It unlocks many opportunities for customization as well as new features for your phone. Some people find these new features worth the risk of possibly breaking the warranty.

You can't, unfortunately. This is dependent on your internet connection. If your iMessage is particularly slow, the only way to fix it is by upgrading your internet service.

Depends on what you mean by 'safe.' Jailbreaking voids your warranty, so if you have a software problem with your phone after jailbreaking it, you will have to pay for the repairs (if you have a hardware problem, they may not even notice it's jail-broken). You can also edit things that are not intended to be edited and do cause software problems, so if you don't know what you're doing, it's dangerous to edit the operating system. And no, jailbreaking is a one-way process. Once it is open, you can't 'shut' it again.

If you are texting a person who also uses an iPhone and you have internet access, it won't cost you but if you don't have internet or the receiving party doesn't use an Apple device, it will cost you.