I commonly use Acrobat docs to study. Problem is, I cannot highlight parts of the text so I can go back and read just those portions again. Much like a highlighter in a textbook. Does something like this exist?
In theory Acrobat reader supports functionality like that (and bookmarking as well), but the vast majority of PDF files are not set up to allow the reader to use that functionality. It needs to be explicity allowed in the document, and most PDF generators don't know how to do that (or do know but have it turned off by default and their users don't know about such features).
Personally i prefer using the foxit reader to read all my PDFs and i strongly recommend it. Its just 1 MB in size and it opens the PDF in a flash ! You can also select text like in adobe. You can find it here
It cant highlight text in colour like you want though . It can just select text and copy it