Finding red birds:
- Enter "bird" in Google image search
- Add "&imgcolor=red" to the Google URL so it looks like this: http://images.google.com/images?q=bird&imgcolor=red,
- Replace "red" with "blue", "green", "teal", "purple", "yellow", "orange", "pink", "white", "gray", "black" and "brown" to get other colors
Still, watch out for possible copy right violations or poor image quality when using pictures taken from Google in your PowerPoint presentations.
Thank you Ashish for pointing this out to me.