You have a few options here to consider.
Conventional 10% down would be 17,500
FHA 3.5% down would be 6,125
There's also CHFA and similar programs which require 1,000 down.
Then there's a program in Denver and Littleton which gives you the down payment and it cost you nothing.
contact me if you would like more details.
thank you for your time,
Tim 303.522.2960 or firstname.lastname@example.org