Sony Style lists the 600 as available in black, red, and silver. The 300 is listed as available in navy blue, rose, and silver. I'm not sure I see where the confusion is, especially when you look at the pictures on Sony's website.
And here are the pictures:
Seems pretty clear what the colors are and what they look like when compared to each other. The 300 is obviously blue and pink, while the 600 is obviously black and red.