The Color Run is the only 5k I've signed up for in years. Spending money and making the effort to travel isn't really appealing to me since I'm not competitive. The Color Run is worth it, though, just for the experience. It is far from competitive. The field includes many walkers and a ton of kids and the vibe is just fun.
I have participate with my tween daughter the last two years and it has really piqued her interest in running. The "Festival of Color" at the end was a highlight for my daughter and I would do it again even if I had rainbow snot for weeks.