I would like to have the colors of my Macbook's keyboard backlight change either permanently or on a cycle. If this can be done in terminal, let me know. I don't want to at all ever open my computer.
Changing the color of your display or keyboard backlight is impossible to do programatically, unless the manufacturer designed it with that capability to change color and to do so using software controllers.
It is highly likely that this is not the case, as it is not common except in very specific circumstances (for instance, the backlight on my old Nokia phone's keypad could do this, and I have an external USB keyboard that has different colored backlight options, but cannot change them programatically). If you want to change the color of the backlight and this path is not already available to you, you will have to open the computer up and swap out the light(s) yourself.
If you would like to change the back-light color, or even just the actual color, of the keyboard, you could try a colored Mac keyboard cover.
Here's a couple of websites to get you started: