What causes chanages in color?

I've been struggling trying to get a nice pink lily color in my perennial/cottage garden. The problem is that the color is not predictable from season to season or day to day. The Algarve (one picture) often shows up a light maroon. Sometimes, though, it's a perfect shell pink. A new one for me is Belgrado. It has bloomed almost all white with a bit of pink on the edges and also that light maroon I see in Algarve. No blooms the lovely shell pink I see when I Google "belgrado lily." And it doesn't look like the difference is that bug-a-boo problem of blues in catalogues.

I'm guessing the differences are from temperature or moisture. True?

I've seen several posts that talk about lilies being "reliable". Does this have to do with color?

I don't have the color variation problem with my yellow or "red" lilies.

I'd appreciate whatever thoughts you have.

TIA
LAS

I have noticed temp and rainfall made a difference. Our temps were cooler and more rainfall this year and the blooms were vibrant in color. Last year less rain and warmer and the colors were duller.

These are a few this year.