Colorado is a no fault state
You are free to date at any time. However discretion is advised especially with regard to introducing the children to new partners. While the law allows you to date new partners it doesn't stop the emotional reaction that you may get from the children or from your spouse. I have seen the costs of a divorce rise significantly when a new love enters the scene.
Keep a low profile while the divorce is proceeding
Involving new partners can upset the children and may complicate parenting agreements. Divorce is hard enough for children. Try to be sensitive to their feelings. Do not force too much change on them early in the divorce process.