I'd go candy blue all the way! Frame, hubs, beadlock rings, etc. Get a black seat cover to clean the look up. Can't go wrong with black/blue/yellow. Having red parts with that mix doesn't look the best IMO.
Some ideas for blue/yellow (click to make larger):
02-yellow-honda-trx400ex-qotm-atv.jpg
400ex blue laegers.jpg
00' 400EX - GT Thunder 450 stroker, custom JE 12.5:1 piston,
+7mm stroked crank, HD stroker rod, HRC cam, GTT full race porting, +1mm intake valves, FCR 39 carb, CRF timing chain, Denso IXG27 iridium plug, full Hinson 8 plate clutch, Desert Toyz Supercooler w/ SPAL fan, UM airbox w/ UNI, CT Hi-Output exhaust, Roll LOBO II F/R, LT PEP 8 click ZPS piggyback fronts, PEP ZPS rear, YFZ brakes/450R master, CCP stabilizer, Hiper Tech beadlocks, Durablue X-33, TAG, Quadtech, ASV, AC, IMS, RAD, Works Connection, Galfer..
05' Kawasaki KLX 110 - Fast 50's springs F/R, HRC cradle, Rox risers, FLY fatbars, NGK CR6HIX iridium plug, Twin Air filter