I'm personally not a fan of coloured seatposts and stems, bars can
look ok but stuff like headsets, QRs and hubs can look really sweet. Slippery slope...
Aesthetically it's about balance I think, getting a little bit of your blingy colour choice in every 'corner' of the bike (ie QRs, seatpost clamp and headset, maybe chainring bolts). I'm glad you're talking about contrasting the frame, far too many people on here try to match the frame
There are programs online that let you change component colours so you don't buy the wrong thing, an easy and very quick one is (ok it's for a BMX):
http://roadhouse.s3.amazonaws.com/Stric ... ver10.html
This thread needs pics though
PARTS FOR SALE:
vintage Brooks Professional saddle | Specialized FACT CX fork | Columbus fork | Reynolds 531 fork | Avid Arch Rival v-brakes | various 700c, 27" and 26" wheels | vintage Weco hubs (fixed/freewheel) | vintage Raleigh ladies frames + lots more!