The Musicolor Method works well with beginning children. I have personally used it with 3 year olds to 8 years old to even 12 year olds.The difference is that if younger, I go slower.
The songs are exercises in disguise and you can move rapidly through them if they are focusing on one song a week. In my school, all of our teachers present one song at a time and use tape or a binder clip to prevent them from going further.
Note: Our Musicolor Masterclass teachers all have access to the printable songs individually which is a great way to have guaranteed novelty each week. A new song!
Also, older kids can just say the color names instead of the words if they feel to babyish.