
1. The obvious reason. Tickled Pink and Sunriser are both pink.
2. Moonglo and Sunriser may both be celestial names, but the thing is they're OPPOSITES. I wouldn't give a night-themed kid a day-themed horse anymore than I'd give Rainbow a gloom-themed horse. I think "Shimmer" sounds like a more fitting name for Moonglo's horse. In fact, I can almost picture in my head what Shimmer looks like, as being a horse with silvery night-themed colors.