How do you allocate unearned income from jointly held accounts when married couple are residents of two different states. This is for state tax return purposes.

Married and filing jointly for federal income tax.  Unearned income is from jointly held accounts.  Couple are residents of two different states: Colorado and New York.  How is the unearned income allocated for state income tax purposes?  Can one person claim all of it? Does it have to be shared?