Learn what to do when the startup process takes longer time.
Applicable for ColorOS 5.2. Check your ColorOS version in [Settings] > [About phone].
If the startup process is taking a longer time, then you may have enabled too many applications in Startup Manager. (This function allows Startup of the applications to boot and startup in background). You can optimize the Startup process by the settings in Startup Manager.
On the phone screen, go to [Phone Manager] > [Privacy Permissions] > [Startup Manager] and disable applications that are not important on the startup of the device.