Resizing images using PIL dramatically changes colors

I use the following code to resize an image using PIL

img = Image.open("in.png")
resized = ImageOps.fit(img, (200, 200), method=Image.ANTIALIAS)
resized.save("out.png")

But the colors of the output image look very different. Here they are for comparison, the big one is the original:

What's even weirder, when I open them using the ubuntu image viewer, they look the same. But not on Windows or MacOS.