Excellent suggestions. I love ponytails, but I do get bored with them.
I really love the idea to add in colored clip-in extensions. Especially in the present time when rainbow hair color is trending so heavily. Adding clip-in extensions is also no muss-no fuss with no risk to your natural hair color.
A pony with loose waves and/or curls are so soft and sassy. I love that as well.
If you get tired of your pony, you can just twist, wrap and pin it up in a bun. Viola.