There are some japanese manufacturers who make bulbs which look silver when they are off, but shine amber when illuminated. I may eventually switch to those, however you have to be careful to make sure the bulbs are compatible with the US market bulb sockets. I think the japanese and US sockets are usually a slightly different shape.
You could also try what I did. Mask off the side of the bulb that will face in (away from the diffuser) and spray paint the outer side of the bulb with high temperature aluminum paint. It looks sliver most of the time, but the the amber light from the inner side of the bulb bounces off the reflector to provide enough illumination for a turn signal.
BTW, that Maxima looks much better without those silly orange bands around the bumper. Of course, almost all cars look better after this mod...