Colo. Rev. Stat. § 31-25-529
Failure to pay the whole assessment within said period of thirty days shall be conclusively considered to be an election on the part of all persons interested, whether under disability or otherwise, to pay in installments. All persons so electing to pay in installments shall be conclusively considered to have consented to said improvements. Such election shall be conclusively considered to be a waiver of any right to question the power or jurisdiction of the municipality to construct the improvements, the quality of the work, the regularity or sufficiency of the proceedings, the validity or the correctness of the assessments, or the validity of the lien thereof; except that, with respect to local improvements authorized in section 31-25-502(2), the owner for each property included in the district shall retain all rights otherwise existing by contract or by law against parties other than the county with respect to the financed energy efficiency improvement or renewable energy improvement.
C.R.S. § 31-25-529
(1) This section is similar to former § 31-25-518 as it existed prior to 1975.
(2) This section was originally numbered as § 31-25-528 in House Bill 75-1089 but was renumbered on revision in 1977 for ease of location.