Unfortunately the lowest published fare on CO (for September) is $385+ tax (U fare). AA and UA's lowest fares (for example) are roughly the same for that time period. February fares go as low as $200 + taxes (L class), so CO may very well publish lower fares for the fall between now and then (though inventory availability would be a different story).
This appears to be a good example of the "new" revenue management -- that is sell high fares well in advance, adjust (lower) the fares closer to departure according to loads.