Is there a particular occasion / setting that you would like to wear them?
These shoes, though, have the potential of being the focal point of the entire outfit, so I wouldn't do too many designs that may cause the shoes to get lost, though you could do multiple colors.
For a casual look, tan / beige jeans comes to mind, the lighter neutral color will allow the shoes to really pop. White would work, too, though being so bright may lessen the impact of the "pop", and a darker color like grey or black may cause the darker shades in the shoes to get lost. Blue jeans seems TOO casual to allow these shoes to pop to their fullest.
I would go with a red top, also, for the fullest effect, to complement the red being the dominant color in the shoes. You could go with a t-shirt and allow the shoes to become an accent to the whole casual look, or a pullover sweater for something a little more preppy, or even a red blouse or button front for something more dressy-casual.
Tan khakis would also be a good choice, with the above mentioned tops.
Tan dress pants would be a good choice for a full on dressy outfit, but I could see a lighter grey, or even black being a good choice, also, for a dress pant, as the shoes are dressy, perhaps with a red, or a darker blue dressy top.
These shoes would look fabulous, also, with a red dress, or a red skirt with really any solid color top, or even a plaid skirt of similar colors (to complement), especially with bare legs or neutral nylons. Even with a pastel colored top, your legs would be the neutral that causes the shoes to pop. Colored nylons, though, would likely take attention away from the shoes. White may work, though I'd like the shoes to be the brightest thing. Even black would work, if it's quite sheer; black opaque would cause the black ankle strap to get lost, and that is a cute feature of the shoe, so sheer black would allow some contrast to allow the cute ankle strap to be seen.
I hope this helps.
