The Princess Royal was gorgeously dressed for her wedding to the Prussian Crown Prince in 1858 as shown here.
The Royal Collection has posted this in color, accessible here. On 17 June 2009, The Prussian proposed this list of persons on the Alexander Palace Time Machine Discussion Forum: "Augusta (m. Frederick), Wilhelm I (f. Frederick) (to left of minister), Frederick & Princess Royal (kneeling), who is the older gentleman in blue?, Albert (in centre), Leopold I of Belgium (to right of & behind Albert), Alfred (in front of Albert), Edward (in front of Leopold I), Arthur (Victoria's hand on his shoulder), Leopold (tiny boy, facing away, in front of Victoria), ?Alice (girl in pink with blue and white flowered wreath), ?Louise (on L) and ?Helena (on R) (poking out from behind Queen Victoria), Victoria, Duchess of Kent (behind Alice, ?Louise and ?Helena), Duchess Augusta of Cambridge (formerly of Hesse-Kassel (to right of Duchess of Kent), Prince George of Cambridge (to right of Duchess of Cambridge & Alice), ?Princess Mary Adelaide of Cambridge (to right of George of Cambridge).”
According to the Wikipedia article about her dress, "The dress was manufactured by Mrs. Darvill, designed by Janet Fife, and composed of a rich robe of white moire antique; ornamented with three flounces of Honiton lace. The design of the lace consisted of bouquets in open work of the rose, shamrock, and thistle in three medallions. At the top of each flounce on the front of the dress was wreaths of orange and myrtle blossoms, the latter being the bridal flower of Germany, every wreath ended with bouquets of the same flowers and the length of each being so graduated as to give the appearance of a robe hemmed with flowers. The apex of this floral pyramid was formed by a large bouquet worn on the girdle. The train, which was of the unusual length of more than three yards, was of white moire antique, trimmed with two rows of Honiton lace surmounted by wreaths similar to those on the flounces of the dress with bouquets at short intervals."