For more on the meaning of colors for the color red. Orange is the color of social communication and optimism. From a negative color meaning it is also a sign of pessimism and superficiality. For more on the color orange. With the meaning of colors, in color psychology, yellow is the color of the mind and the intellect. It is optimistic and cheerful. However it can also suggest impatience, criticism and cowardice. For more on the color yellow.
The blood has several types of white blood cells including neutrophils, bands, eosinophils, basophils, monocytes and lymphocytes. Each fights infection in a different way. Neutrophils, for example, are one of the body's main defenses against bacteria. Neutrophils kill bacteria by ingesting them. Neutrophils can ingest five to 20 bacteria in their lifetime. Another type of white blood cell is called bands. Bands are immature neutrophils.
Our immune system works around the clock, year in and year out to protect us from infection and from cancer. The body has three kinds of blood cells. Red cells carry oxygen. Platelets make the blood clot when it is supposed to. White blood cells fight infection and inhibit cancer.