Lovely colors! There really is the explosion of vivid purples and yellows in this composition. It makes me think of an exploding floral star. Composition is strong and colors really pop. One thing that would improve the appeal of the image is to get the center portion of the flower in sharper focus. It is juusst I touch soft. All points of the flower could be in sharper crisp focus if you increase the F-stop to something higher than 5.6 (for greater depth of field). A macro of an object can be very tricky if you have some points of the flower higher or lower than where you are focusing. Hence some softness to some of the elments. With adjusting the aperature to get greater DOF you will have to adjust the shutter to a slower speed to expose it correctly.