A rule of thumb if you have to find brown in RGB: use a bit of red, slightly less green, then a tiny bit of blue.

That kind of proves the point. How many of those rules of thumb are you going to have to formulate to express in RGB what's trivial to find in HSV?

Unfortunately I've already formulated them after working so much with RGB in low-level graphics code, pre-hsv() CSS, and some image editing software.

Actually, that sounds kind of like a fun challenge game: name a color, then try to guess RGB values for that color.

I've gotten pretty good at doing the reverse operation(given an RGB value, guess the color) because I'm red-green colorblind and that's how I figure out what color something is :)

The converse game exists: http://yizzle.com/whatthehex/

Edit: Actually, so does the “guess the RGB given the colour” direction, but I don’t find it as fun: http://mallory.jemts.com

jacobulus might have been referring to certain color spaces that are optimized for human use instead of for computer manipulation, such as HUSL (http://www.boronine.com/husl/). HUSL gives you a slider that actually changes the apparent brightness of a color to your eye: whereas HSL thinks that bright green is just as “light” as dark true blue, and HSV/HSB thinks that true blue is just as “bright” as white, HUSL colors with the same “lightness” actually do look equally light. Another human-optimized color space is CIELUV (https://en.wikipedia.org/wiki/CIELUV).