Yeah....what they said.
Interactive Drop Shadow tool...I use it too much these days. LOL
I used that for the backlit effect on the Gazebo in this design, just select the size (Sm/Med/Lg) you want, change it from black, to the color you want & tweak til it looks right. This is a little different, since it's in the design....but you should be able to use it the same way for your purposes. Although, I would think that using Photoshop or Photopaint might be better for raster graphics like you're using here.
