I'm sure if it were blooming here in the warmer part of the season, the colors would develop more.
Mind you, daylily colors here are frequently not quite as those seen in the hybridizer images (taken in greenhouses? in the South?). Apart from our cool nights, we are very arid here, and that IMO also impacts bloom color. Once in a great while we will have an usual day during the season when the humidity is relatively high (prior to a rare summer shower), and then the color on the daylilies is amazing. In general, though, that is not the case.