The blossoms have a variegated green and yellow exterior and a primary yellow interior. My first effort was to isolate a single flower against a generic red background (a chair in our library).
I decided to crop the shot as a square, and I ramped up the color saturation. I like the color combination, and I thought the increased saturation matched my aesthetic sensibility. The issue was the depth of field. This was shot at f/8 with my 90 mm macro lens, focused on the flower's top front edge. Because the macro lens allows me to shoot from very close range--a matter of a few inches--the depth of field is quite shadow. Close inspection reveals that the back edge of the flower, just 2 or 3 inches further away, is quite out of focus. There is something to be said for that, but I decided to shoot at a much smaller aperture to pull more of the flower into reasonable focus.
This next shot, which is of only a portion of the blossom, was shot at f/36. This was an 8 second exposure.
The back edge of the flower is in better focus, but still not great. I like the composition of this shot better than the first, even though (or perhaps because) it only includes a portion of the blossom. Again, I increased the color saturation.
Here, for the record, is the same shot in black and white.
In this case I darkened the red and lightened the yellow. I didn't think the black and white was quite as effective as the color version.
A few days later I spent some more time with the lilies, in this case against a textured white background (our bedspread). First a shot of an entire flower.
This was shot at f/16, which produced fairly good depth of field for the flower. The background was far enough away that its texture is sufficiently out of focus to eliminate it as a distraction. But there is a different problem with this composition--the camera is positioned too low relative to the flower so that very little of the flower's yellow interior is visible. So following is a second shot taken from a higher angle that does a better job of revealing the flower's yellow interior.
It is evident that the texture of the background is a significant element in the shot. That's not all bad, but I thought I would take one more shot in which I separated the flowers further from the background to eliminate it as an element.
Here there is very little remaining background texture (except a faint line running diagonally in the upper right. I like this shot, although it almost looks like the background has been removed artificially. A matter of artistic preference.