Most apartments will allow these, but no matter the policy always cover them yourself before move out! Even if you do not have the matching paint the material to fill these holes is only about five dollars at any hardware store!
If there is something you do not want installed in the apartment, maybe to save space, ask the building if it can be removed – that way you do not have to deal with working around it yourself!
This is my favorite! If you want to add character to a space but cannot use paint, use wall stickers!
Maybe a chair or coffee table can bring some needed character! Lastly, have fun with the small things like shower curtains or fun pieces in the entryway!