Yellow bone marrow - Oukotsui

Japanese: 黄骨髄 - おうこつずい

…The size and weight of the entire bone marrow is comparable to that of the liver, and bone marrow with active hematopoiesis is red, so it is also called red bone marrow or red marrow. On the other hand, areas that do not produce hematopoiesis and have been replaced by fatty tissue appear yellow, and are called yellow bone marrow or yellow bone marrow or fatty marrow. It is currently believed that if we trace the ancestors of red blood cells, white blood cells, and platelets present in peripheral blood, we arrive at a common mother cell. …

From [Bone Marrow]

…the soft tissue that fills the medullary and cancellous cavities inside bones. There is red bone marrow (also called red marrow) and yellow bone marrow (also called yellow marrow), the former being involved in hematopoiesis. In fetuses and immediately after birth, the body consists only of red bone marrow, but as the body grows, it gradually becomes fatty and is replaced by yellow bone marrow, and it loses its hematopoietic ability. …

*Some of the terminology that mentions "yellow bone marrow" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…骨髄全体の大きさと重量は肝臓に匹敵し，造血の旺盛な骨髄は赤色を呈することから，赤色骨髄または赤骨髄ともよばれる。一方，造血を行わず脂肪組織で置き換えられた部位は黄色に見え，黄色骨髄，黄骨髄または脂肪髄とよばれる。　現在では，末梢血液の中に存在する赤血球，白血球，血小板の祖先をたどっていけば，一つの共通の母細胞に行き着くと考えられている。…