I send my car (2000 S500) to my independent MB mechanic to change Tx Oil last week. Today I saw a small patch of red color oil in the garage which is where the transmission located. I thought MB oem transmission oil is colorless or light yellow. I told him to use OEM oil. But I was busy and left the car with him. I still have to go back for the oil leak but i want to confirm the color before I start the case. Thanks for advises.