The CMY colours (commonly mistaken for Blue, Red and Yellow) are the answer when printing as mixing any two will form one of the darker RGB colours. The mix of all three CMY colours creates Black, although in practice this is very muddy.
White blood cells, like all blood cells are created in the bone marrow from certain stem cells. However, some lymphocytes are created but undeveloped or immature.
Lymph flows through the lymphatic vessels and contains infection-fighting white blood cells known as lymphocytes. So, lymphoma is a type of cancer of the white blood cells that begins in immune-system cells called lymphocytes. It is similar to leukemia, which is a cancer of the white blood cells in the blood system. White blood cell cancer may grow in many parts of the body such as lymph nodes, bone marrow, spleen, blood and other organs.