In most jurisdictions you can get a felony conviction expunged as long as you haven't had any other run-ins with the law. Each state is different as to how long you have to wait or what type of felonies can be expunged. I would use Avvo's find a lawyer tool to find a local attorney, it shouldn't cost that much to get this taken care of as long as you qualify.
The issues you raise are state law issues, with the timing and ability to have convictions sealed, annulled or whatever varying from state to state. Contact a local lawyer using the AVVO find a lawyer tab and make the telephone call.
No information provided in response to these questions can be relied upon in any way without further personally consulting with Attorney Kerrigan and Attorney Kerrigan consulting personally with you regarding your specific legal situation.
You can not get a felony or misdemeanor conviction in Colorado sealed. Colorado does not offer expungement of adult convictions and does not allow for any conviction to be sealed unless it is a class 6 felony drug use after 10 years.
The information provided in this answer does not create an attorney-client relationship and is not considered to be legal advice.