Cost: Varies, can be inexpensive
Shiro and Kuro lolita are not substyles in the same sense as the other substyles on the list. Shiro is Japanese for White and Kuro is Japanese for black. Shiro lolita is a monochromatic lolita style where everything is 100% white. White dress, white accessories, white shoes, the whole nine yards. Kuro is Japanese for black and it’s the same idea. Everything is black; accessories, clothing, shoes, etc.
With both Shiro and Kuro lolita, makeup is done as normal, and hair can be any color. Shiro lolita should not be confused with Shironuri, which is a Japanese street fashion which involves painting one’s face white.
Shiro and Kuro lolita are rarely done alone. Usually, if someone does Shiro or Kuro lolita, they have a friend who is doing a matching outfit in the other color. The duality of light / dark, black / white is compelling and so pairs of Kuro and Shiro lolita have continued to pop up in photoshoots and magazines over the years, though it was more in style in the earlier days of lolita.
Because the only real rules for a “shiro” or “kuro” coordinate are that they are monochrome, shiro and kuro can really be done in any other substyle. You could have a gothic kuro coordinate, or a classic one, or even a sweet one.
Note: purists consider something not to “count” as shiro / kuro if there is any other color in the coordinate, including gold/silver.
What about other colors?
While a lot of illustrated guides to lolita fashion have tried to add in other monochromatic styles like Pink (usually written as “pinku”), blue (written as Ao, Mizuiro, Sax or Saxon) and red (written as aka or reddo), there isn’t really a tradition of a large group of people stylistically and intentionally making monochromatic coordinates in any of these colors. It’s the pairing of Shiro with Kuro and the history of people repeatedly doing it over the span of many years that makes it significant.