The Facebook anarchist custom lightsaber group is a great place to learn about these little gems of info

phil and his team are quite active on there, as well as here in the forums.
But yeah, I also recently learned about changing colors and quick connects, so I'm happy to pass along the info.
And yellow is a fantastic color. Keep in mind that a fully charged 12W yellow will look a little green, but just let the battery drain for around 10 min or so and it should settle into a super warm yellow hue for the vast majority of the battery life