how long do you have to live in colorado to become a resident?

Answer 1

For the purposes of higher education, a student must reside in colorado for 1 full years prior to first day of classes, in order to pay in-state tuition prices. There are special rules applying to whether one can claim residency if the student is under 22.
You can access the information here:
http://www.collegeboard.com/about/association/international/residency.html

For voting purposes, residency requirement is 30 days, and registration before election is 29 days ... which means if you want to vote in an election in colorado, then you will have to move there 60 days prior to the election, in order to satisfy the residency requirement prior to registering, and the registration requirement prior to voting.
http://www.infoplease.com/ipa/A0781452.html

I don't know for what other purposes you would be inquiring, so cannot address more than these two.

Answer 2

Under federal law all you do is register to vote and you are a citizen of that state. You can do this the moment you enter a state.

Other ways are to get a state Id or drivers license. Basically as soon as you choose to be a resident you are considered one.

If a person were inclined to do so they could conceivably be a citizen of all 50 states within a 50 day period. But the tax returns would be a nightmare unto themselves.

Answer 3

6 months and a day