dash lighting upgrade?

I need to do something about the dim dash lighting in my '66. The two outside gauges are barely visible at night. I don't know if the voltage is low in the dash harness and a new light switch might fix things, or if maybe some bulb upgrade would help.

Also, I've seen the replacement dash bulb covers in some of the parts catalogs. Both this '66 and the '65 I had 20 years ago seem to have the normal yellowish incandescent glow. What color is the dash lighting supposed to be? Does anyone have any tips or suggestions for me before I jerk the dash out?