Question does anyone know why American military aircraft used to be painted yellow and silver
As far as that specific scheme goes, we are talking about aircraft of the USN during the interwar period, the scheme is frequently referred to as "yellow wings". At the same time, the US Army Air Service/Army Air Corp painted their aircraft first blue and yellow and later olive drab and yellow, with minor differences, and trainer types stayed all yellow through most of the second world war. So, interwar naval aircraft.
Let's picture an F3B, a really good looking little fighter made by Boeing. We see an aluminium dope applied to the fuselage, lower wing and the undersides of the upper wing and horizontal stabs.^1 The "chrome" yellow is easy: visibility. We haven't always known that white stands out or is easier to see, conventional wisdom led to the TO for hi-vis - yellow - upper surfaces. Remember as well that at this point, the plane guard would have been a destroyer, and there wouldn't necessarily be another aircraft close enough to assist in locating a downed aircraft.
The silver colour is less concrete. The History of Flying Colours does a good job of walking one through the decision making process that ends with aluminium dope, I'll paraphrase. Fabric is susceptible to damage from weather and the like. Doping the fabric increases the useful life of fabric. The dope is effectively clear, so up through late 1915 and early 1916 we see a great many tan aircraft in the sky. That colour is frequently referred to as Clear Doped Linnen. After the war, Britain and France have the middle east to worry about. Well, now we have the sun and heat to contend with so a red oxide dope is used to deal with UV rays and aluminium pigments are rubbed in to the dope - this is why you'll see red interiors and silver exteriors even when you're only looking at one side of one piece of fabric - to reflect heat. It's implied that the heavy USN presence in the Pacific and similar conditions being the norm there lead them to aluminium dope.
Now for the big question: why the hell was the scheme held over after metal aircraft became the norm? There are a great many views on this. My personal belief is that this is simply another example of tradition persisting in the navy long after usefulness. 200 years of tradition unimpeded by progress, as they say. Another possibility takes us again to 1919. The war to end all wars had ended. Why would aircraft need to be camouflaged if they weren't ever going to fight? In support of this view, the US Navy went to the Intermediate Blue^2 over non spec gull grey in the early forties when America entering the war was a relative certainty.^3 That said, you'll find no shortage of material saying the change had more to do with not having a silver paint that stuck to metal surfaces so who knWar.
I think I've answered your question, if not then my apologies.