What kinds of stars did people wear at the concentration camps?

Answer 1

It appears you are asking about the prisoner badges the Nazis used in the camps. There were many, and a complex system of translating their meanings. Look below for an explanation:

The double triangle or Star: Two superimposed triangle ressembling a Star of David

• two yellow triangles "Yellow Badge" denoted a person of Jewish descent.
• red inverted triangle over a yellow triangle indicated a Jewish political prisoner.
• green inverted triangle superimposed over a yellow triangle indicated a Jewish "career criminal" or an habitual convict.
• purple inverted triangle superimposed over a yellow triangle indicated a Jehovah's Witness of Jewish descent.
• pink inverted triangle superimposed over a yellow triangle indicated a Jewish sexual offender (see the pink triangle below).
• black inverted triangle superimposed over a yellow triangle indicated "asocial" or "lazy" Jews.
• a voided black inverted triangle (border) superimposed over a yellow triangle indicated a person of jewish descent who was convicted of "miscegenation" and labled a "race defiler."
• yellow inverted triangle superimposed over a black triangle indicated an Aryan woman convicted of "miscegenation" and labled a "race defiler."

Triangle markers: reserved for non-Jewish prisoners.

• red triangles marked political prisoners (communists, liberals, social democrats, trade unionists, Freemasons and other secret societies suspect to the Nazis, and anarchists.
• green triangles marked "career criminals," those with more than one conviction. Green triangles often worked in the camps as Kapos.
• blue triangles marked emigrants who were forced into lablor camps.
• purple triangles marked Jehovah's Witnesses or "Bible Students," generally religious pacifists.
• pink triangles marked "sexual offenders," primarily homosexual males, very rarely homosexual females, and almost never rapists, paedophiles, or zoophiles as these convicts were most often put to death.
• black triangles marked "asocial elements" and "work shy." Such groups who were often stereotyped so were Gypsies (later marked by brown triangles), mental patients, alcoholics, beggars, vagrants, draft dodgers, lesbians, prostitutes, and drug addicts.
• brown triangles later were adopted to mark people of Roma descent, Gypsies.
• Inverted red triangles marked enemy POWs, spies, and deserters.

In addition to the primary badge designation, other markers were used:

• Letters in triangles marked the country of origin of the prisoner:
  • F - France
  • H - Holland
  • B - Belgium
  • I - Italy
  • J - Yugoslavia
  • N - Norway
  • P - Poland
  • T - Czechoslovakia
  • S - Spain
  • U - Hungary

• Bars over the inverted triangle indicated additional classifications. Colors of the bars matched the already established classification system.
• "NN" markings in yellow indicated Nacht und Nebel prisoners, those who had been alleged to have been involved in any activity that was deemed dangerous to the state.