Some of prints, some white, black, and various other colors. Is there any signifigance to the colors or the way it's worn? Some just have heads covereed, others covereed with the black things from head to toe. Also see some men with the skull caps and others that don't.for men it's easier -- Moslems follow the OT rules like Jews that men should cover their heads when in prayer.
For most, this is the skull cap or Kufi, but in Central Asia they would wear something like this
while Bohris and Syedna Bohris (two sub-sects of the Shia mostly based in the subcontinent) wear this traditional cap
For women there are various types of coverings - basically again they follow the OT rule that married women should cover their hair. In some parts this is just a shawl 
and also in Iran this is the chador
I found this image on the net for you
The basic rule is to cover your head -- as in the OT.
Different types are based on a combination of which religious "school" (i.e. way of thought) and which culture you come from. The Hanafi or Salafi way is the full burqa or niqab, the Ayatollah's force the Chador.
Different cultures have different types of head-dress, but the Wahabbis all dress the same no matter what culture -- they like to pretend they are all Nejdi Bedouins from Riyadh