http://www.nintendo.com/consumer/systems/gameboy/compatibilitychart.jsp

That should tell you all you need to know about the compatability. Short answer: Yes you can. 

Update to point out main points:

- Firstly, inserting an original GameBoy game will display up to 4-10 colours. The colour scheme can be changed using special palettes. 
 
- A small number is said to possibly not functional properly as sometimes there may be scrambled images, sound problems or missing graphics.

- Screen size can be changed by pressing L + R buttons. This may however distory the images.

To add to this, to change colour palettes, here a few key presses you can perform (you have to do this at the startup screen:

- Brown: Up directional key
- Blue: Left directional key
- Pastel mix: Down directional key
- Green: Right directional key
- Red: Up + A
- Dark Blue: Left + A
- Orange: Down + A
- Dark Green: Right + A
- Dark Brown: Up + B
- Gray: Left + B
- Yellow: Down + B
- Reverse: Right + B

Hope this was a bit more informative than my short answer :).