Does anyone know how to remove the Colorado state sales tax refund from my return. I was not 18 for the full tax year.

You don't have to have been 18 or older to claim the TABOR credit.  And, bear in mind that TurboTax is generating the credit based on information you've provided, so if your responses in the Colorado portion of the interview were correct, you're most likely entitled to the credit.

A full-year Colorado resident under age 18 can claim the credit if:

• They have a Colorado tax liability or 
• They're claiming a refund of Colorado wage withholding from a Form W-2

According to Line 34, State Sales Tax Refund in the Form DR 0104 Booklet:

If you are a full-year Colorado resident who was under 18 as of January 1, 2023, you may claim the state sales tax refund only if you have a Colorado tax liability (line 14 must be greater than 0) or you are claiming a refund of Colorado wage withholding on a W-2. Your return must be postmarked by October 15, 2024.

[Bolding mine.]

See also the Colorado Department of Revenue's Taxpayer's Bill of Rights (TABOR) Information for more information.