not because she really likes orange as a color.

I'm pretty confident orange is Alya's favorite color, actually

I mean I have no evidence for this aside from the dominant color of her plaid shirt and how she dyes her hair, but how Rose dresses is the sum total of anybody's argument for her favorite color being pink (where arguing that Juleka's favorite color is purple does at least have the supporting evidence of her mirror frame in "Reflekdoll"), so