What Colour Goes Best With A All Black er Spaniel??

I am going to purchase a Outward Hound™ Dog Excursion Backpack. The Bag comes in 3 (three) colours. They are Red and Black, Light blue and grey or maroon/red with maroon and red dog bones on it. I have no idea on which colour to pick. Thanks :) PS, the er spaniel is a girl.