My first time using self-striping yarn and amazingly, the socks match perfectly!
I've made self-patterning socks before - and they were fun - but the striped ones were particularly pleasing.
The yarn is Stray Cat Socks 'Tranquility' with a matching blue solid for the heels and toes.
I knew that using a heel flap would likely distort the gusset/instep stripes somewhat, but in fact they worked out only one round narrower than the rest* and you can barely see the difference.
*That's with 64 stitches on 2mm needles.