The red part on the exchange display is a request. The green part on the exchange display you are using is the offer. Red and green are another name for buy and sell if that's what you mean.
Another meaning, for example, is that you have an item that you want to sell at the price you want. Finally, you are ready to add your item to the bid list. Those who are interested in your item will ask for a purchase price below the price you want. Then it's up to you to take action against the item.