@GoodVibesGorgeous
You’re most likely right. The G5 Twilight we never got was going to be an Earth Pony and some of those concepts were tweaked and carried over onto Sunny.

Probably from unused concept arts for A New Generation. Like, back when it was supposed to be a full reboot featuring G4 characters (one of the ideas for Twilight Sparkle and Applejack surely evolved into Sunny Starscout and Hitch Trailblazer).

It’s cool to see how the influences of past iterations of MLP have come together to create the G4 series. I’d wonder what G5 draws from.

Oh, and Pinkie losing her wings, too.

I never actually knew Fluttershy got her wings starting with Generation 4.

@Dogman15  
It should. Lauren also said that she also based Rarity off of Glory too and that’s unfortunately not here.
 

 
Makes sense too since the coat and mane colors match perfectly.

This chart will need to be updated.

@Red Cedar  
Not only to retain some of the audience  
If you look all the colours that hasbro use to make there toys what are the most used colours ?  
If you are correct on the trademark then that means Hasbro just forced the changed colours to not invest in to much new colours in their plastic injection lines.  
That’s my bullshit theory but I like it ;)

I call BS on the trademark reason given. I’ve looked through the online registry of the U.S. Trademark Office and as near as I can tell none of the original ponies’ names from the 80s were ever trademarked (and Applejack wasn’t trademarked until 2010). The names Rainbow Dash, Pinkie Pie, Rarity and Fluttershy, however, were trademarked (around 2004) because they all featured prominently in G3/3.5.
 
The more likely reason (but not so PR friendly) is that Hasbro used already trademarked names out of convenience, and because they wanted to retain some audience in the transition from 3.5 to FiM by using already familiar names.
 
As for Applejack, I can only assume Hasbro allowed her to be used out of some sense of tradition. She is the only pony to have existed in all four generations.

Imagine Pinkie as a pegasus. She’s hyper enough in [I]two[/I] dimensions of travel.

Wow, I remember when I was looking for this picture every day. I had just got into the show, and was trying to remember where each character came from.

Add spike…

^ Coincidentally, half of the show most awesome moments wouldn’t happen, and the ponies backstories would be much different.

Imagine if she hadn’t made Rainbow Dash into an actual character and Firefly had been turned down outright?
 
 
…that’d be pretty sweet.