Steampunk is a sub-genre of science fiction, fantasy, alternate history, and speculative fiction that came into prominence during the 1980s and early 1990s. Steampunk involves a setting where steam power is still widely used—usually Victorian era Britain—that incorporates elements of either science fiction or fantasy. Works of steampunk often feature anachronistic technology or futuristic innovations as Victorians may have envisioned them, based on a Victorian perspective on fashion, culture, architectural style, art, etc. Other examples of steampunk contain alternative history-style presentations of such technology as lighter-than-air airships, analog computers. Read more on wiki
Steampunk fashion is based off of Victorian styles, but embellished and influenced by steampunk fiction. Colors also tend to be subdued and are rarely bright in color. Colors are commonly neutral, although red and blue can sometimes be found. Colours can be used such as deep burgundies, bronzes, dark gold, burnt umber, dark purples, dark forest green, dark teals (sea blue), cream, vintage, autumn colours and worn colour palette.
Worn colour palette
Autumn Neutrals (right)
chocolate raspberry, creamy tan, burgundy brown, dusty navy & juicy olive
Fall Brights (left)
warm brick, gold, deep lavender, sweet apricot & dusky teal
Outfits are often tied together by at least one prominent accessory, such as goggles, parasols, top hats, or some kind of mechanical gadget. Steampunk women often wear dresses complete with petticoats, corsets, and some sort of head wear, often a small, feminine top hat or a floral pin. It is not uncommon, however, to see a steampunk lady dressed as a pilot, air pirate, or engineer; steampunk is a genre of adventure and women are often eagerly welcomed to join the fun. Outerwear often includes pea coats, riding jackets, flight jackets, and carriage coats. Women often wear skirts or dresses, but pants are also common. Corsets are also very common and can be under- or over-bust. Elegant gloves are a common sight, but adventuring females often don fingerless ones.
Read more on http://steampunk.wikia.com/wiki/Steampunk_fashion