Auto Mechanics to Quantum Mechanics: Any Questions?

It's that time again.

For those new to the Playground, I have a schtick I do at the beginning of each class where I let the students ask absolutely any question they have, any question at all, from auto mechanics to quantum mechanics. Some former students asked me to revive it on-line, so every couple of months I trot it out here. So, if you've ever had a question you always wanted to ask or something that's just been stumping you, here's your chance. Ask away and I'll get to as many as possible in this week's posts.

Here's one for you: Why is pink the only pastel among the primary or secondary colors to have its own name? (Grey and tan don't count here) Why would make sense to say, "That's not red, that's pink," but not "That's not blue, that's baby blue"?

So, any questions?