If you could
provide a photo it might help confirm the following thought.

Most canna
cultivars do prefer full sun, adequate nutrients and warm temperatures as
stated.

Cannas are
similar to many of our semi-tropical plants in that the growth rate (metabolic
rate) is dependent upon extended day length, temperature and local growing
conditions. The flowering cycle at this time of year will be accelerated causing
the individual bloom cycle to be somewhat reduced. They bloom, complete fertilization
(where applicable) then fade to be replaced by new blooms more rapidly in midsummer
than late spring or late fall. The bloom color will change in the same manor
but it may suggest a need to provide more nutrients.

Best,

Kent

Thanks for your response. I am including 3 pics. Unfortunately, the one that might have best shown the contrast turned out a little blurry. I am surprised by some of the ones that still have the bold color. Some of them are a couple days old and would normally have faded to the paler color by now. Maybe it's bcs part of yesterday and almost all of today was overcast. The paler color is very pretty but I do prefer the bold version. This is the first year in a long time that I have grown cannas, so I'm not very familiar with their habits. I do water copiously and fertilize on a regular basis.

Your cannas
appear to be very healthy, very well cared for and absolute great! For your
location I would expect to have seen some canna leaf roller damage but there
seems to be none. I congratulate you on your effort.

You stated
that this is the first year in a long time growing cannas. Could you share information
as to where you purchase or received this group of new cannas and was there a
cultivar name listed?

(IF) you
purchased these plants as growing potted cannas locally or rooted plants shipped
to you, I suspect they are a result of one of the new seed strain cultivars.
This would account for the somewhat varied color in each plant compared to
another individual plant as seen in the first photo.

Regards,

Kent

Thank you! They do look pretty healthy. I purchased them in a pot at Lowe's but cannot remember the cultivar name and don't know if I kept it. Will look and see.

I think you are so right! I just assumed the flowers were fading. Never considered them being different kinds. I'll have to be more observant. Thank you so so much!! A mystery solved!