Pressing a wrong key sheds blue light on whole screen in iTerm Pressing a key that doesn't do anything, sheds a blue light on the screen for a moment, and it's quite annoying.

For example, in iTerm, since pressing Down Arrow Key doesn't do anything, so it sheds blue light on the screen to let me know there is something with what I'm doing, but it's pretty annoying.

I use Vim for development, and time and again, I press Esc to switch between different modes, and this thing annoys a lot. Is there a way to get rid of it?
Still have no idea what's wrong with it, but searching on Google gave me the following command to execute, and it did the job:

sudo killall coreaudiod