Automotive Colors
Having worked in the industry for many years, I concur that silver hides the dirty better than any other color.
Black is gorgeous on any vehicle - when it is clean. I own a '92 Black Camry and it will be my last black vehicle. Perhaps not a bad choice for a car, but not ideal for a rig that will be going off-road or in the woods, etc.
White (and any solid color) is the easiest to touch-up.
Metallics and pearlescent coatings acheive a different appearance depending upon application method. The effect pigments (aluminum, mica, etc) float and orient themselves quite differently when sprayed. The coating process must be held in much tighter control to achieve consistent color. A brush or aerosol touch-up will never exactly match the factory spray applied coating. Also, remember that these are primer/color basecoat/clear topcoat OEM systems. Very difficult to achieve a match in a one-coat repair process.
Toyota (and Lexus) use gray primers. While Honda/Acura coatings are a step below in chemistry with regards to performance vs. Toyota/Lexus, I do lke their practice of using color-keyed primers. Toyota/Lexus use gray primers. When I do get a deep scratch on my silver Runner it reveals the gray primer. Deep scratches in the Galactic Grey color will not be as noticeable over the gray primer.
From a coatings science perspective (and without getting technical), black and white colors are the most "prone" to chipping - all else being equal. Black and other dark colors will also exhibit the effects of acid rain degradation much, much more then lighter colors. High chroma reds and yellows are the most prone to color fading. These are all factors that the coatings scientist minimizes through proper formulation. Obviously each color formulation incorporates variations aside from the various pigmentation differences.
IMO 4Runners look great in ANY color. I still like the green used in the 3rd generation and whish they brought that color back. Being the boring scientist, I will probably always own metallic silver or gray. (Although I am eyeing a new blue that Mazda is planning on offering on their new power retractable hardtop Miata MX-5 next year!)