If you don't like how the classic boot logo looks, start logo, for iPhone, then a tweak available and without jailbreak allows you to modify it as you like. We are talking about something that can be installed on the iPhone without having to jailbreak beforehand, it being compatible in iOS 11 for users right now.
In the video clip below, you can see how this personalized boot logo is installed on the iPhone, all based on the discovery of an image that you want to use. After you have the image ready, you can set it in the iPhone in the special application that must be installed, even without jailbreak, as it can only be used in iOS 11.
Normally, changing the iPhone boot logo in iOS was possible only after performing a jailbreak, but since we can install any applications we want without it, things are simpler. Changing the boot logo should not affect your phone's warranty, since you are not changing the software itself.
To be able to change the iPhone boot logo in iOS 11, you will first need to install the TweakBox application from this page and accept the associate developer profile. After this procedure you will only have to choose the image you want to use as boot logo and set it, everything is very simple.