I can hardly see those darkened edges, Tunde... I have to try very hard to see what you're talking about :o)

So, while it's not that visible to me, maybe a few questions can help solve your 'problem'...

Did you try this with another lens? Perhaps a different lens could be better (or worse) in juxtaposing or resolving the red edges against the green background (think of red-cyan fringe or chromatic aberration...). I did some red-cyan fringe correction and it does seem to have an effect on some edges, but not all...

Did you try with a wider aperture? Maybe diffraction at the edges is causing the red 'overlay' against the green... Although f/9 shouldn't be too much of a problem.

Did you try a different color setting in your camera (muted colors, saturated colors, etc...)..?

Do you have the same problem with a less color-contrasting background (say yellow or brown)..?

And what if you reproduce this shot with only natural light with a few reflectors added..?

We do not see things as they are. ǝɹɐ ǝʍ sɐ sƃuıɥʇ ǝǝs ǝʍ