The problem with summaries of bad check laws on many sites is that they are incomplete. That's the case with the summary of Colorado's bad check laws that you found. Colorado Revised Statutes § 13-21-109 provides the civil damages you'd be liable for to the store. It gives the store a choice of 3 remedies, in addition to the face amount of the check, that it may pursue:
1. Actual damages suffered by the store; or
2. A reasonable posted contractual fee of $20, plus as collection costs, 20% of the face amount of the check, but not less than $20; or
3. If certain requirements have been met, three times the face amount of the check, but not less than $100.
Furthermore, IN ADDITION to any of the 3 remedies outlined above, the store is entitled to get court costs and attorney's fees should it prevail in the civil suit. In addition, if it chose option 2 above and won the suit, it would also be entitled to it's actual costs of collection (if it exceeds the 20% provided for in that option.) That could push your final total damages much higher than the amounts provided in the 3 options above. The store may have already incurred legal fees and collection costs that it is tacking on to the check, and if the store must file suit or otherwise expend more effort to collect, expect the fees to continue to pile up. On the other hand, if you won the suit, you'd be entitled to collect attorney's fees from the store. However, if you clearly owed the check, you are not likely to be the winner in the lawsuit.
You can always make a counter-offer and see if the store will take it. If they won't, you either pay what they ask or wait for them to sue you. But if they do sue and you lose, the judgment may be for even more than they are seeking now depending on how much in costs and fees they incurred along the way.
Note, too, that passing bad checks is a possible violation of at least two Colorado criminal statutes, as well.