IMO it depends on the shade and on what you want to do. For showing you should use brown tack anyway. For dressage you should use black tack. For any other situation just go with your own feeling about what looks best.
My pony of a lifetime was a strawberry roan...until the one year we clipped her and she went blue!! LOL
I 'dressed' her in burgandy for everyday life and bright white for show days. She had lush brown tack. (saddle was probably worth more than the pony, but had to be custome made and was worth every penny..... £400........20+years ago!)
Yep Candyman is strawberry roan.He looks good in most colours to be fair. I use white on him for special occassions as his legs are a nice deep rich chestnut so white boots look great. Most of his every day stuff is blue,ie headcollars,numnahs and tendon boots.
I think they'd look great in most colours, apart from bright red and pink, and maybe lavendar, baby blue.. But I think yellow would look really nice, or navy blue, white for shows, even purple I think would look nice! xx
Rosie is a strawberry roan. She came with tack which is a brown bridle and a black saddle - until now I'd not even considered that they didn't match
She currently wears a brown newmarket Rambo Handy Pad - numnah, looks good with her brown sheepskin half pad. Before that she had a purple numhah - that looked good too.