I built a Lego kit recently, for literally the first time in 3.5 decades of life (we had a huge box of Lego growing up, never any kits or sets). I took such pleasure from seeing all the creatively-repurposed parts, but I was really surprised by some of the colors they used for internal components and other little things. I had no idea they made Lego in those colors, much less that there are variously-colored internals on big kits.
I had white, black, yellow, blue, green, red, and clear, and that was it. And sure it makes a ton of sense that they have a bunch more colors but.. still.. mind blown.