I am answering my own question for the state of Colorado. The following web site defines in detail what is acceptable for an exclusion.
https://www.colorado.gov/pacific/sites/default/files/Income20.pdf
Then I looked up my federal money market fund to determine what type of government obligations it contains.
https://investor.vanguard.com/mutual-funds/profile/VMFXX
Scroll down and see a list of the government obligations contained in the fund. Only the "repurchase agreements" (15.1% of the portfolio) aren't included in excludable interest (reference the first web page above).
So I am entering 84.9% of the 1099 dividends as excludable interest for this fund.
