Thank you thank you thank you everyone for your wonderful responses. Martha, I really appreciate all the thought you put into your response. Those were my thought patterns too and yes the colors do look different in person. The light green silk is irridescent so the color is a bit off in the pic.
I had also tried a dark grey, brown, navy, hunter green, irridescent rust, burgundy, and cream. The black does make the leaves pop, but I think it was a bit heavy. The gold was a little too discordant a note and it just didn't feel right to me. I liked the blue and thought it would represent the sky and that is my second choice. My favorite is the darker green and Martha, you were right and I feel this would celebrate his life and IMHO, green is a neutral--all you have to do is look at nature. Barbara, I agree with your insight too--it does make the center with the green trim around it stand out and help your eye travel around the piece. There isn't a flower that doesn't look good against a green background.
Last but not least, is Jeannie, the recipient's input and she immediately nixed the light green and blue (she is a more earthtone browns, reds, golds person). We agreed about the black and she was iffy on the gold but liked the darker green which is really a medium olive tone. So the darker green it is.
I am very touched by all the responses and comments. It is a special project and we loved Dino very much and still miss him.