Sometimes when the market is red it can also be a good time to enter the market if carefully watched. Not all green ends up with profit and not all red ends with loss too.
The ideal time to entry is in red market because it is the time when BTC is cheap. A green market means BTC price is increasing, so we can't by BTC at a cheap price. People may think the green market is a good time to entry, may not have the purpose to hold a long time. They just hold for a short time and take small profits. While for people who target for the long term investment, they must choose the entry time in bearish season (red market). Of course, green market doesn't guarantee for profits, it totally depends on the way (strategy) we trade.
Things like this are certainly basic knowledge so that we are not wrong in making decisions which can result in losses,
It is important to know when to buy and sell,
the most important thing is keep trying to learn and much better.