"Well..." Does he want to say it? He wonders, then decides, idle tone and all, "I've just been wondering how difficult it'd be to reach other people if we wanted to. The ministry sent a message out that one time."

You know. Just been thinking about that.

"But the clock? Actually... every time we wake up, it's a different colour." Uh- "It runs on colours. About... every hour shows a new one. I can show you sometime if you want. I can't do anything with it."

So Senku can do whatever he wants with it. It's nothing but a waste (of time!) for him.