The nature of the agreement matters as does the context and you'd have to know more facts to reliably answer. The default rule is "no" your signature wouldn't count to sign on behalf of your wife, but there are exceptions that might apply.
There are also multiple ways that your action could be interpreted depending upon the context.
One possibility is that a contract is formed between you and the other party, despite the fact that your wife was the original intended contract party. For example, if the contractor intended to enter into a contract with you and mistakenly wrote down the wrong name despite the fact that both of you intended that you be the signatory and the wrong name was merely a clerical error.
One possibility is that your wife is bound but not you, on the theory that you had apparent oral authority to act on her behalf (or perhaps a power of attorney authorizing you to do so). A person is bound to a third-party when someone with apparent authority acts as their agent in a transaction, even if that person didn't have actual authority to take that action. But, if you sign in your own name, rather than in her name expressly purporting to sign on her behalf as her agent, it is not clear that this was suffice to show apparent authority.
A third possibility is that only your wife is a permissible party to the contract and not you, and that you do not have actual or apparent authority to act on her behalf.
If it is a business agreement with your wife or involves investments, you do not have any common law actual authority in Colorado to act on her behalf (that common law authority was expressly overridden by the Married Women's Property Act, Colo. Rev. Statutes §§ 14-2-201 to 14-2-210) without your wife's express permission to do so, and would generally not have apparent authority to act on her behalf solely by virtue of being her husband in the absence of a power of attorney to that effect or an express oral communication of your authority from her to the other party to the business contract. Of course, if you were also an officer or employee in her business that might be another thing entirely.
The original version of part of that act has been on the books in Colorado since two years before it became a state in its territorial laws in 1874 currently read as follows (the language was made gender neutral and stripped of archaic terminology effective August 8, 2018):
Colorado Revised Statutes § 14-2-208. Married person may contract
A person, while married, may contract debts in his or her own name and
upon his or her own credit, and may execute promissory notes, bonds,
bills of exchange, and other instruments in writing, and may enter
into any contract the same as if he or she were unmarried. In all
cases where any suit or other legal proceedings are instituted against
the married person and any judgment, decree, or order is rendered or
pronounced against the married person, the same may be enforced by
execution or other process against the married person as if he or she
Likewise, you certainly couldn't legally sign a government contract that your wife was entitled to sign only in her official capacity as an officer or employee of a government agency. Government contracts are only valid when signed by someone who has actual authority to do so, even if everyone involved mutually believed that the person signing it had apparent authority to do so in Colorado, and there is some rather harsh case law to that effect.
If the agreement is for "necessities" for the family, arguably a contract is actually formed between you and the other party, even though your wife was the originally intended signer, and that this is also binding on a non-signatory spouse because a wife is legally responsible in Colorado for purchases of necessities entered into on credit by her husband (and visa versa), because the other party to the contract is a third-party beneficiary of your spouse's legal duty to support you. See here. This was the historical common law rule and there is little recent case law to determine if this old rule remains good law. Arguably later legislation and constitutional developments have implicitly superseded that rule and debt collectors prefer not to rely upon it if they can avoid doing so.
It is also fairly plausible that you did have apparent authority to bind her to a contract as her agent, even if you didn't actually have authority to do so, in a way that it wouldn't be plausible in the case of a government contract or business or investment contract, in a contract to purchase necessities on credit (or even "luxuries" for the family), since you are presumably an adult decision maker in the family.
If you are the owner or co-owner of a building having work done on it, it is more likely that you would have authority, than it would be if the public records showed that it was only in her name.
Ultimately, a trier of fact would have to sort through the context and facts, including the nature of the contract, to determine whether or not it would be binding upon her.