I want to fully clear the terminal, not just scroll down. There are plenty of answers to this question already. However, I have found that the colour scheme gets changed (to the default one?) after doing this. I am using termite as a terminal emulator.
reset does a lot of things (among others it resets the terminal modes, which you don't care about here) and you just want to do one thing.
Use clear, which will also attempt to clear the terminal's scrollback if it can.