Please see the following from the Colorado booklet on page 21:
Line 12 Qualifying Charitable Contributions
Taxpayers who make charitable contributions that would be eligible for a federa...
See more...
Please see the following from the Colorado booklet on page 21:
Line 12 Qualifying Charitable Contributions
Taxpayers who make charitable contributions that would be eligible for a federal income tax deduction, but do not claim federal itemized deductions on Schedule A of form 1040, 1040SR, 1040NR, or 1040SP, might be eligible to deduct a portion of their contribution on this form. We recommend that you read publication Income Tax Topics: Charitable Contributions if this applies to you. Use the following worksheet to determine your qualifying contribution.
(a) Did you itemize your deductions on Schedule A of federal form 1040, 1040SR, 1040NR, or 1040SP? Yes No
(b) Did you deduct charitable contributions on Schedule A of federal form 1040, 1040SR, 1040NR, or 1040SP? Yes No
If you answered Yes on either (a) or (b) above, enter $0 on line 12; you do not qualify for this subtraction. If you answered No on both (a) and (b) above, continue below.
But as I read your post, you did itemize on your federal return, so you would not able to qualify for this subtraction.
As you can see, your Colorado return starts on line 1 of the Form 104, which comes from line 15 on your 1040. But line 15 on the 1040 is after your itemized deductions, so your charitable contributions are already included when you start your Colorado return.