Blue is the best, suites her better. The only reason younger fans like her pink is because of the merchandise. Disney marketing decided to make Cinderella's gown blue instead of white and silver as it is in the movie because she looked too bridal. So they ordered it blue, powdered or sky blue for marketing and commercial purposes and gave Aurora the pink look, more girly. Hope this settles it! Blue is better on her, makes look more regal.
Because they think they have to merch with one princeess per dress color. Example: Belle's dess is yellow, so no other Disney princess can be merched with a yellow dress. This is why Aurora is merched with a pink dress insted of blue. Because Cinderella's dress is blue.