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.'