https://tax.colorado.gov/cash-back
"To receive Colorado Cash Back, an individual must meet the following criteria:
Be at least 18 years of age on or before December 31, 2021;
Be a Colorado resident for the entire 2021 income tax year;
And file a state income tax return for the 2021 income tax year or apply for a Property Tax/Rent/Heat Credit (PTC) Rebate.
Anyone moving to Colorado in 2022 is not eligible for this refund mechanism."
Non resident don't get paid for several reasons but the biggest would be accounting. If everyone that paid income tax in Colorado gets a check and the current $2 million in expenditures to write and send would end up costing more than the surplus amount.
Kevin Durant plays for the Nets. They play in Denver once per year. He makes around $500k per game. Does he get a check? The guitar player in a band that does a week in Telluride? Hillary Clinton for one speech in Aspen?
There has to be limits.