My DD's Brownie troop is going to be in a Christmas parade and the parents thought it would be cute if the girls wore matching gloves and scarves (red for Christmas). I thought that would be easy to find but so far no luck!
For the scarves I would buy red fleece and make scarves, you can either just cut it into strips and fringe the ends or they could knot them if you wanted to spend more time, money and effort.
For the gloves look for the "magic" stretch ones that are $.99 at or cheaper at Walmart or I've had luck at Walgreens they usually have the plain colors. My DD had to wear red or white when she was in a baton group for the Christmas parade and this is what we bought for the group.