Yes, at the moment all coins remain green against bitcoin. Bitcoin is going lower in its history. I think lots of investors have done this. As bitcoin going lower & lower from several days many people or investors choice alternative. This is why altcoins going green. But there is a limit for down. So any time bitcoin can move for up again. But at the moment at least for 2/3 month altcoins remain green I think.
If you are really watching the market now, you can tell the real situation, bitcoin is getting greener and greener and its dominance is still big.
Majority of the altcoins are not really growing, people are more investing in bitcoin now, but don't worry, the right time will come.