2 Colo. Code Regs. § 601-10-4.07
Prior to Bid opening, a Contractor may withdraw or revise a Bid after it has been deposited with CDOT. Withdrawal of Bids may be made either in writing or in person; however, any Bid withdrawn for the purpose of revision must be redeposited before the time set forth for opening of Bids in the Invitation for Bids. A Bid may not be withdrawn after the commencement of opening of Bids for the project, except as provided in Section 4.14.
When a Bid is withdrawn, the Individual requesting to withdraw the Bid shall provide proper identification. The withdrawal and the identity of the Person withdrawing the Bid shall be documented in writing by CDOT. Withdrawn Bids will not be opened.
Prior to Bid opening, a Contractor may withdraw or revise an Electronic Bid after it has been submitted to CDOT. Withdrawal of Electronic Bids may be made through the Bid submitting software; however, any Bid withdrawn for the purpose of revision must be re-submitted before the time set forth for opening of Bids in the Invitation for Bids. A Bid may not be withdrawn after the commencement of opening of Bids for the project, except as provided in Section 4.14, or if options available within the Electronic Bid software are elected to be exercised by the Bidder.
2 CCR 601-10-4.07