For those who have and are planning on going with Rick's clear diffuser and have had difficulty in finding an amber turn signal replacement bulb, the following is the Honda part number that you can order from your local Honda dealership:

33303-S2R-003

Please make note that I have not tested them out yet, but have only been able to visually compare the clear stock one with the amber one. They are identical in size, shape, and connection and only cost ~$3 each.

According to airgate, the bottom bulbs on our cars are the same as the Civic Si's sidemarker bulbs.

 

WRS2K, I'm glad you found these and posted the information. Civic Si sidemarker amber bulbs work well for the marker lamps in the headlights.

Keep us posted once you try them.