admmad said:....What happens in other flowers, such as chrysanthemums also happens in daylilies.
...
The higher the temperature (above the optimum) the less pigment (the lighter the colour). The lower the temperature (above the optimum) the more pigment....
I can not agree fully to this opinion - it depends on the cultivar.
Some daylilies need heat to show intensive colors - best examples in my garden are Dakar, Rolling Raven and Black Pearl
Cold temperatures:
Warm temperatures:
I have other dark cultivars in my garden that suffer from heat and look ugly.
This color intensifying effect can be seen on some lighter colored ones too - best example here is Ursula Heuss (German cultivar, bread in colder climate):
Cold temperatures
Warm temperatures
I bought the cultivar for its clear light colors - as we usually have warm temperatures here the plant looked muddy everyday - so I gave it to a friend in alpine climate where it is beautiful pale.
So my conclusion is - temperature may cause paler flowers but the opposite is possible too.
