Color seems kinda dull

Convert the color profile to sRGB and it should look better on your browser.

Otherwise, it looks fine to me. :S Focus is on the flower too.

It is rendered a bit too dark on my system. If it were lightened up a bit, I think the colors would look a bit more vibrant.

It doesn't matter much what ISO you use, so long as the aperture and shutter speed are OK with respect to other considerations.

Use of f/5.0 did a good job on the background, but the background would be even more out of focus had the aperture been wide open (f/3.5).

When it is cloudy (no direct rays of the sun falling on the subject), the scene contrast will be low.

strange... I cant set it to 3.5 even on manual. The lowest it would go is 4.5

ziggie216 wrote in post #5898781
strange... I cant set it to 3.5 even on manual. The lowest it would go is 4.5

The maximum aperture changes as the focal length changes, on the 18mm end of that lens, you're able to get 3.5, at 50mm, you can't get anything wider than 5.0.

I had to get it out and set it up for the 28 mm focal length you were using, and you're limited to f/4.5

The center of the flower is out of focus as well.
It is a bit dark, could use a bit deeper dof and a bit more contrast. Flowers like this are tough to shoot. They will look best if you can get the dof deep enough to handle the flower without making the background too clear.