I have a window with a yellow stained glass window pane that catches the light of the setting sun, which makes for a pretty wicked "natural" color filter. This is what happens when you don't know how to use Photoshop, you find other ways to get creative. Anyway, that's where this shell is, and how it got this color and glow. It's resting on the wooden frame of the window pane. The glass itself often proves for an interesting background.
Here is the other side of the shell.