It is the mind of the First Presidency and Apostles expressed at one of their late regular Council Meetings, that you adopt as soon as it can be done conveniently the practice of brethren wearing white pants while doing Temple work. This change would necessarily do away with the long white Shirt usually worn [b]y them, and admit of their wearing the regular white shirt, with collar and white tie if they choose to do so. The adviseability of this change will at once suggest itself to you. * P.S. This change in dress need not be introduced into prayer circles.
[Source: George F. Gibbs to John D. T. McAllister, Nov. 3, 1896, in Anderson, Devery; The Development of LDS Temple Worship, 1846-2000: A Documentary History, http://amzn.to/TempleWorship]