Complementary colours are pairs of colours that contrast strongly when compared to each other.
The green foliage would require a red-toned flower to demonstrate complementary colours.
Check some of the forum discussions on complementary colours for suggestions on using colour for contrast.
The blossom has a great deal of character and depth. The lighting on the bloom is dull, however. The background tree is somewhat distracting. Noise lends a bit of an old-fashioned feel to the subject, just too many distractors to make this an exception rendering of the subject.