Camellia color has me stumped

I have been tending to the camellias and azaleas at the nursery for about five years and this has me stumped.
Kramer's Supreme is listed as a red, or bright red, most of the time it never holds its color or comes out a medium pink. I have one right now at the store that's espalliered and it is red. The 5 gallon bushes and even the 15's are all medium and sometimes a coral pink. A customer came in and said that they've had theirs in the groun for a year and it's in almost total shade and it's more a dark pink than red.
What gives?!

Are there any growers out there or camellia experts that have an answer to this? Is it soil condition? Sun exposure? Acidity? All of the above? This is for my edification so I can pass it on to customers.

Hi Greendini,
I'm not an expert, but I thought I'd show you a photo of my Kramers Supreme. It's in Del Mar in almost full shade with somewhat sandy soil. I water regularly and fertilize about every two months with Camellia fertilizer (I don't know the brand name, but it's for acid loving plants). As you can see mine is definitely more toward pink.

Thanks Cozette! It's a gorgeous flower, just not anywhere near the red that most sources say it should be.
I asked one of the grower reps the other day and he says that they have variable results as well and theirs are in shade.
I guess it's just one of those things that haven't lived up to it's origins.
I usually recommend Tom Knudsen or Mrs. Charles Cobb.

Thanks for the great picture!