Amendment 64 proposes amending the Colorado Constitution to:
- regulate the growth, manufacture, and sale of marijuana in a system of licensed establishments overseen by state and local governments;
- allow individuals who are 21 years old or older to possess, use, display, purchase, transport, and transfer—to individuals who are 21 years old or older—one ounce or less of marijuana;
- allow individuals who are 21 years old or older to possess, grow, process, and transport up to six marijuana plants, with certain restrictions;
- require the state legislature to enact an excise tax on marijuana sales, of which the first $40 million in revenue raised annually must be credited to a state fund used for constructing public schools. The excise tax must be approved by a separate statewide vote; and
- require the state legislature to enact legislation concerning the growth, processing, and sale of industrial hemp. 
Read the full text of Amendment 64 here.
 "2012 State Ballot Information Booklet." Legislative Council of the Colorado General Assembly. Research Publication No. 614, page 7.