For what it's worth, here is what a couple of generations of etiquette books have said about the "proper" "traditional" ring-bearer's costume:

1990: Letitia Baldrige, Letitia Baldrige's Complete Guide to the new Manners for the 90's, (Rawson Associates, 1990, New York), p. 271. 'The ring-bearer...[dresses] in satin or velvet shorts (or even knickers with white knee socks) and a silk shirt with a Peter Pan collar.... An option to having a ring-bearer is one or two little boy _pages_. (If possible, all the children should wear black patent leather or white Mary Jane shoes and white socks.)'

1972: McCall's Magazine, McCall's engagement and wedding guide, (Saturday Review Press, 1972, New York), pp. 64, 73. 'The ring bearer is between the ages of four and seven.' 'Train bearers or pages...are boys between the ages of five and eight or slightly older.' 'The ring bearer's costume usually is a white suit with short pants or short white pants worn with a ruffled white blouse, a colored sash, socks and strapped patent leather shoes which may be either black or white. Page boys, though slightly older, are generally dressed like the ring bearer.'

1970: Flora F. T. Bryant and Kendall S. Bryant, It's your wedding, (Cowels Book Co., Inc., 1970, New York), p.?. 'The ring bearer should wear a white suit, one he could wear to a party where he might meet a magician with real live rabbits in his hat. He may wear white socks and either black or white patent leather shoes with straps....'

1969: Elizabeth L. Post, Emily Post's etiquette, (Funk and Wagnall's, 1969, New York [12 ed]), p. 378. '...Pages may be dressed in quaint old-fashioned...suits of white silk or satin of whatever period the bride fancies. Or perhaps they are dressed in ordinary white clothes with...white boutonnieres.' 'Ring bearers and train bearers are most often dressed in white suits, preferably with short pants.' 'Tiny boys and Girls wear slippers with a strap and white socks. If they are dressed in white, their slippers are white, but if they wear color, their slippers are colored, either to match their clothes or of black patent leather or a contrasting color--more often the latter.'