If you want to drink warm water, you can buy a thermos cup, which is black in color and navy blue is more suitable;

You can usually buy a glass or a ceramic cup to drink water. Generally, the inner wall of the cup is white, so it is easy to find out whether there are impurities in the water. Glass or ceramic cups are more environmentally friendly and healthy; Plastic smells;

Of course, you can buy any color you like.