While this is a lovely tutorial, I've met many people who enjoy making neon characters and roleplaying on them. There even used to be a roleplay literally called Sparkle RP, made of of the spiffiest sparkle animals you ever did see.
Main point being, I don't necessarily believe using neon characters to RP should be under "Don'ts". Users should be able to create their character however they feel looks acceptable, without fear of being ridiculed for it, regardless if playing as a funky neon character, or a very real looking one.
However, this is your tutorial, and I'm just sliding in my opinion, hue.
I did enjoy the color scheme of the whole post. Putting the Don'ts under red and Do's under green made it easy to decipher one from the other.
Which brings to mind, when you said color codes, did you mean the numbers for those colors? That sounds like an awesome addition to the tutorial. As an idea, maybe talking about which colors go good together?
All in all, 'tis a neat little tutorial. Thanke for taking the time to write it! +Floof