Neither is wrong.
Ponies were produced in many factories, sometimes even multiple countries and over multiple years, and have variations. Purple paint does sometimes fade to a more pinkish color, but it can also just be batch differences.
They often vary slightly in body color, symbol size, symbol placement, presence or absence of paint beneath glitter symbols, physical size (degree of shrinkage after casting), hair thickness (the spacing of the plugs), lack or presence of a forelock, eye paint color, eye black shade (from true black to brown-black and anything in between), degree and placement of blush, squishiness of plastic and more. It's less common to find to absolutely identical ponies than two that have some minor differences.