That is harsh and somewhat elitist. I'm guessing people could probably say pretty much anything to sound skilled by replacing X here: "What? If you're a web developer and don't know how to use X, then you're not a very good one."
I understand RGB, base-16 and HSL yet this isn't instinctive for me. I might be a below average dev (although my clients and colleagues seem to think otherwise), but I'd prefer a color picker any day before thinking about translation of color codes.
Imagine that the string you plugged into your browser was actually the hash of the hex code for some nonsensical reason. Developers would be no less good or productive since for almost all purposes they're arbitrary constants that happen to be attached to classes like 'blue-primary'.